
@vbarsani
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Physician scientist
Palo Alto, CA
Joined March 2011
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Vali Barsan, MD 🇺🇸 retweeted
Mike 3 things to consider 1) Revenue growth as modeled by sell side analysts and others is not equal to what is in the models of people who actually own stock and trade it, long buy side active funds 2) Pharma equity trades on an earnings multiple not a revenue multiple, margin expansion vs contraction can also explain “above or below” this line and 3) Terminal value assumptions matter - Organizations and management teams that have consistently demonstrated the ability to deliver organic R&D (Vertex) or BD (Abbvie) productivity get rewarded with a management premium/increased terminal value because the bet is they will do it again.
Vali Barsan, MD 🇺🇸 retweeted
picofold.py: a minimal protein structure predictor in ~200 lines of readable PyTorch.
Give it 16 amino acids and it turns random noise into a 3D structure, step by step. I wrote it to demystify protein folding and flow matching for myself. Hope you find interesting! 🧵
Vali Barsan, MD 🇺🇸 retweeted
In language, compute and data has both scaled; in biology, compute has scaled but data has not (yet). A few insights into what it takes to create high quality data for machine learning from the awesome Arc Institute experimental teams. Lots more to come. arcinstitute.org/news/behind…
Vali Barsan, MD 🇺🇸 retweeted
Why do our cells age?
It's not just wear and tear, accumulated damage.
Loss of cell identity takes center stage.
A @Nature review today by @gladyshev_lab and connection with prior work that substantially advances the science of aging.
In the new Ground Truths.
Vali Barsan, MD 🇺🇸 retweeted
Wild 24 hours for AI and lots of different proposals have been made.
TLDR; the only *tangible* new fact is that OpenAI and Anthropic are going to have embedded 3rd party evaluators from unknown organizations with Dario floating METR as a possibility. Having 3rd party evaluators is smart as there is no Section 230 style liability shield for model outputs and showing a “duty of care” will be important in future litigation. Several internet companies might have gone bankrupt without Section 230 so limiting liability really matters.
There are minimal investment implications from this single new fact, but I do think that for anyone who wants a “smoother for longer” cycle then most constraints are good: wafers, watts, real rates and spreads. Excessive regulation is a different matter but I don’t think we are anywhere close to this even if the vector changed over the last 24 hours.
To summarize the events:
Dario made the most maximalist proposal of the weekend: embedded 3rd party evaluators, a national regulatory regime for models beyond a certain capability/ingredient threshold, a broad international regulatory pact between democracies, stricter limits on compute/distillation for China and then a different international regulatory regime that encompasses China. Before there is a national regulatory regime, he wants a Sherman act waiver so that Anthropic can safely coordinate with OpenAI and other frontier labs without antitrust fears. TBF, this latest proposal is much less maximalist than some of his prior proposals like “Policy on the AI Exponential,” where he advocated for an FAA for AI. I believe he is sincere in his beliefs. And despite all the protestations, all of this would also probably be good for his business over the long-term.
Sam agreed that embedded 3rd party evaluators were a good idea and stated they would implement them. Again, this is smart as should help limit future liability.
Elon said “Dario is right” and later specified that “Dario is right that there should be some oversight. Peer review of AI by competitors is the right way to start this off.” This would be a MPAA like self-regulatory structure for AI with regular calls between the labs plus a process where each new model is evaluated for safety by competitors for a 1-2 week period before being released. That is *wildly* different from Dario’s proposal and in-line with what David Sacks has been proposing. Elon also stated that nothing was going to slow down open-weight models.
Demis said that Dario’s essay was a “step in the right direction.” Dario also said that he was also open to Demis’ idea of a FINRA like self-regulatory structure as part of his proposal.
David Sacks had a thoughtful post where he said that Dario and Sam should pace unilaterally, called the antitrust waiver a cartel request and denied that METR was truly independent given their ties to Anthropic.
Sriram Krishnan, former White House AI advisor, noted that it would be important to have the 3rd party evaluators come from independent organizations that are not affiliated with any lab, which is basically an indirect statement about the relationship between METR and Anthropic which Sacks was explicit about.
Clem from Hugging Face said they were open to being a neutral 3rd party evaluator, which is interesting especially if Jensen was consulted before that post.
Alexander Wang from Meta noted that alignment would be an increasing focus going forward.
An executive order seems likely after all this and the language in this EO is going to be really important. It is possible to democratize and distribute AI broadly and safely without centralizing it in the hands of a few corporations who might each become more powerful than any single government.
I do not want a few humans in control of intelligence.
I want us all to have our own intelligences that reflect our own values and human variation in all of its richness.
Intelligence distribution over intelligence centralization FTW.
Vali Barsan, MD 🇺🇸 retweeted
Dario has written that we need to “pace the frontier,” and Sam has agreed. People may be surprised by my response: go ahead.
You guys are the frontier. By any reasonable metric — market share, revenue growth, model capability — the two of you have a duopoly on frontier intelligence. You’ve also claimed the lead is widening because of recursive self-improvement.
I don’t see what you see in the lab. If the unreleased models are scary enough that you think you should slow down, I support your decision to be responsible.
But stop pretending you need anyone else’s permission. Stop pretending antitrust law has to be suspended so you can form a cartel. Stop pretending you need a regulatory approval process that supersedes product liability. Stop pretending METR is independent when it is intertwined with Anthropic’s investors and staff. Stop pretending you need those same evaluators to police competitors who aren’t even at the frontier.
Most of all, stop pretending the motivation to slow down is purely altruistic. You face massive product-liability exposure if your products enable a truly damaging cyberattack. The market already punishes models that behave in unpredictable or unauthorized ways. After the Hugging Face episode, it is simply good business for OpenAI and Anthropic to trade some raw power for reliability and predictability. Call it alignment if you want. It is also just giving customers what they want.
Pacing the frontier would also create breathing room for a more intelligent conversation about regulation than Bernie Sanders’ “shut it all down.” China is very unlikely to join a global agreement, as you know, and that has to be taken into account as well.
So go ahead and pace the frontier. You are the ones setting it. The easiest way not to build superintelligence is for you to agree not to build it. Demanding your preferred regulatory framework as the price of that will look like blackmail of the public and the political system. So just do it.
If you do, you’ll buy goodwill for the next conversation. If you don’t, we’ll know this was just another bid for regulatory capture — or an election-season psyop.
Vali Barsan, MD 🇺🇸 retweeted
We have been discussing this for 20+ years. And nothing got better. The opposite. Trials went from being 10 page documents to 300 pages. Orders that were written by pharmacists in the clinic in 30 minutes now take months and multiple stakeholders with “beacon” builds.
The bottleneck for effective cancer treatment is not the science
"It is no longer the science... that is holding back potential cures, but our capacity to try new medicines in clinical trials."
by @RuxandraTeslo @nytopinion
nytimes.com/2026/09/04/opini…
Vali Barsan, MD 🇺🇸 retweeted
This kind of forward thinking already happening in hematologic cancers as well with recent FDA approval based on MRD-negativity endpoint in myeloma. As long as the surrogate is reliably associated with meaningful clinical endpoints, it gets new drugs to patients faster!
Replying to @FDA
@FDA granted accelerated approval for camizestrant today based on SERENA-6: switching therapy when an ESR1 mutation appears in ctDNA, before scans show progression. This is resistance defined, drugged, and tracked at the bedside.
I served as Chair of the Oncologic Drugs Advisory Committee (ODAC) on this trial. My recent @JAMAOnc piece discussed the vote and regulatory issues around detecting cancer before it is seen: jamanetwork.com/journals/jam…
Gene Correction Clinical Trial for Sickle Cell Disease Expanding to Children as Young as 12 healthier.stanfordchildrens.…
Vali Barsan, MD 🇺🇸 retweeted
Many thanks to @carlzimmer at the @nytimes for spending so much time with us and capturing the "magic" of science so beautifully.
"Success can be just as mysterious as failure. Some researchers consistently get experiments to work, earning befuddled admiration from colleagues. Scientists even have a special term for this gift: magic hands.
The idea may come as a surprise to people who don’t spend their lives in labs. Science is not supposed to be magic.
When scientists carry out experiments, they keep careful records, both in lab notebooks and later in published scientific papers. Other researchers use that information to repeat the experiment.
But every scientist discovers sooner or later that essential knowledge is not necessarily written down."
Vali Barsan, MD 🇺🇸 retweeted
Gaining therapeutic access to the human brain is one of the biggest unsolved problems in biomedical science.
Today @nature, we uncover a massive influx of immune cells into the human brain during aging, revealing that the brain is more accessible than previously thought. 1/
nature.com/articles/s41586-0…
Vali Barsan, MD 🇺🇸 retweeted
For my first post, I’m sharing a letter @NVIDIA signed on why open models matter.
AI will transform every industry, power every company, and be built by every country.
Open models strengthen safety and cybersecurity, accelerate innovation and diffusion, and enable sovereignty.
The world needs both frontier closed models and frontier open models.
images.nvidia.com/pdf/Open-W…
If learning flows in only one direction, economic value converges toward the owners of the learning infrastructure rather than the creators of the knowledge itself.
When tokens go down 90% by the end of the year and then another 90% next year, everyone's opinions on artificial general intelligence and superintelligence are going to change radically
I'm currently on an unlimited GLM 5.2 bittensor subnet and I can tell you your behavior changes radically when token prices plummet





















