Open science challenges in preclinical biology

Most of what we think we know about APOE4 is probably wrong.

Eight thousand papers, forty proposed mechanisms, and room for maybe one. Help us find out which.

Papers and Findings opens November 4th, 2026

One proposed mechanism, as MecCog represents it

Rectangles are claims about the state of the system. The words between them are what gets you from one to the next. Colour is how far the evidence supports that step. Select any of them.

protein synthesis
↓
mechanism unknown
↓
impaired recycling
↓
aggregation
select a stepEach step is a separate claim with its own evidence and its own confidence. Finding and weighing that evidence is the work this challenge breaks into pieces.

well supported partly supported weakly supported nobody has explained this step

After Figure 1 of the Moult and Darden preprint. The colours record the schema builder's own evidence assessment. Choosing this mechanism as the example does not mean it is better supported than the others.

Why this needs a challenge

The literature does not add up

8,000
papers published on APOE4, perhaps a billion dollars of work, some with over 100 figure panels
~40
distinct biological mechanisms described across them
1–3
what comparable gene-disease relationships would lead us to expect
≥90%
of the reported mechanisms are therefore likely misleading, unless APOE4 is a very unusual variant

The problem is not that we do not know enough. It is that most of the things we think we know are probably wrong.

This is not a story about incompetence or fraud. Known fraud in Alzheimer's research is rare, and great ingenuity has gone into the experiments behind these papers. The problem is volume. Fewer than half of reported preclinical findings replicate, and replication effect sizes average under 20% of those first reported. No person and no lab can hold 8,000 papers in view, let alone weigh them.

The goal

Pipelines that know what we know

Create AI powered pipelines that generate a comprehensive knowledge representation of a disease: what is known and not known about the mechanisms underlying it, where the key gaps are, what experiments would fill them, and what it all implies for therapy.

The strength of AI here is scale. Humans can critically assess the literature, but the size of the task is overwhelming, and that is the primary reason we have a replication crisis. Preliminary work shows that properly instructed AI systems can handle this kind of complexity. Current systems also make mistakes and cannot be trusted, which is the whole difficulty. How do we build pipelines for this task that hold up?

The form of the AI systems is up to participants. Structure is imposed on the submissions so they can be compared against one another.

The work

Five tasks. The first one is open.

Task 1 · open now

Papers and findings

Find the papers bearing on a mechanism hypothesis, and extract the relevant primary experimental findings. Tasks a and b, November 4th to December 1st, 2026.

Task 2 · later

Evidence assessment

Assess the strength of the evidence for and against each finding. Task c.

Task 3 · later

Mechanism and confidence

Infer the mechanism steps, and assign a confidence to the proposed mechanism. Tasks d and e.

Task 4 · later

Experiments

Suggest the experiments most needed to close the evidence gaps. Task f.

Task 5 · later

Therapeutic implications

Examine what the mechanism implies for treatment. Task g.

Take part

What is open now

Papers and Findings, Step 1. Five hypotheses about how APOE4 affects endosome function.

We expected the first two tasks to have existing solutions, given how central literature retrieval is to AI-for-science work. As far as we can tell they do not, and tests within the working group confirmed that both are far from trivial.

We ran an agent collab on Hugging Face in which 38 contributed agents worked together on these tasks across five APOE4 hypotheses. They collaborated impressively and retrieved papers better than the working group had. Performance on extracting experimental detail was very poor.

Participants now get a new set of five hypotheses and are asked to find the relevant papers and extract the detail. This is a pilot, to see whether the challenge and assessment designs are sound.

Assessment

There is no answer key

What the literature contains is itself part of what is being measured, so the assessment methods break new ground and may develop as the project goes on.

Kaggle predefines one ranking metric. CASP predefines a subset and lets assessors add more once results are in. We set out initial considerations without a ranking formula.

Cross-evaluation by participants, each scoring ten othersif submissions are many
Comparison across groups: which papers, which experimentsidentifies the easy results
Each finding's relevance, by the directness criteria
Each finding's effect size, P value and system, against the paperhard for current methods
Manual inspectionwhere necessary

Background

The biology, for anyone who wants it

None of it is needed to take part.

Why APOE4, and why Alzheimer's

The lack of effective treatments for Alzheimer's remains the major failure of modern medicine. Between 60 and 70% of people with a diagnosis carry a copy of APOE4, so prophylactics built on mechanistic understanding could at least halve the number of cases.

APOE codes for a small protein of 299 amino acids, the primary means of lipid transport in the brain, whose main job seems to be ferrying lipids, cholesterol above all, from astrocytes where they are made to neurons which need a lot and make little. Most people carry two copies of APOE3. APOE4 differs by one base, which puts an arginine at residue 112 where E3 has a cysteine.

Figure: the two forms of the apoE protein
figures/apoe-forms.png
The one amino acid difference between E3 and E4 is associated with a very large increase in risk. Why?

Odds ratios for people homozygous for E4, against those homozygous for E3, have been reported as 20 to 30 in neurologically confirmed cohorts. E4 is uncommon in most populations, yet most people with a diagnosis carry at least one copy.

Figure: risk by age and genotype
figures/risk-by-age.png
Risk of late onset Alzheimer's by age and APOE genotype, European ancestry population. Two copies of E4 reaches close to 90% by age 80 in these data.
Which mechanism hypotheses are investigated

The mechanisms assessed include a set classified by changes in apoE protein properties and interactions, and a biologically broader set. This draws on a Moult and Darden preprint.

Figure: molecular stage mechanisms
figures/molecular-mechanisms.png
Each begins with an effect of APOE4 on the protein's properties. The top branch starts from apoE4 being less thermodynamically stable, with two hypothesized consequences: that it provokes the unfolded protein response in some cell types, and that it is more open to intracellular breakdown, with one fragment disrupting cell function. All four are apparently supported by data.
Figure: the broader set
figures/broader-mechanisms.png
Three main branches cover mechanisms affecting amyloid beta, lipids and tau. A fourth collects more diverse ones, and an empty fifth marks that the tree is not complete.
Biology primers

The language. Disease mechanisms are usually described in very technical terms. It is all standard material, and a quick query fills any gap. We suggest teams that include biology expertise and help with matchmaking, but it is not essential: the main foundation models are biology-aware. Do not be put off by the vocabulary.

Alzheimer's disease. 6.5 million diagnosed in the US today, 13.6 million expected by 2060. Despite 3.2 billion dollars a year from the NIH alone, there is little consensus on mechanism and no effective treatment. Diagnosis requires specific cognitive impairment plus amyloid plaque and tau tangles. Plaque begins decades before symptoms and does not correlate with impairment; tangles come later and correlate strongly. The form of interest here is late onset, a complex trait disease with variants at 75 known loci, of which APOE4 is by far the strongest.

Genetic variants. Each of us carries about two million variants from the reference genome. Most are benign. Some cause disease directly, as one base change in hemoglobin causes sickle cell anemia. Others shift the odds of a complex trait disease, usually by very little, odds ratios under 1.2. Alzheimer's is a complex trait disease, which is what makes APOE4 so strange.

Lipids. Mostly found in membranes. Most are not water soluble, so moving between cells needs packaging. ApoE is the primary lipid packaging protein in the brain.

Proteins. Chains of amino acids, twenty types. The sequence usually stabilizes one folded shape, whose surface lets the protein interact with other molecules. ApoE recognizes and interacts with lipids in ways that are less well understood.

The unfolded protein response. A folded protein is only weakly stabilized against the unfolded form, so one amino acid can leave a significant fraction unfolded. Unfolded proteins aggregate and cause trouble, and cells answer by slowing many processes, protein production above all. Whether this is happening can be read from the RNA produced for each gene.

Cell types. Five matter most here. Neurons, the network nodes. Astrocytes, which supply them with lipids. Microglia, the brain's immune cell. Oligodendrocytes, which make the myelin around nerve fibres. And pericytes, which bridge the brain and the vascular system at the blood-brain barrier. Each signals to the others.

Organizers

Who runs this

Listed alphabetically by surname. Support: BEACON/SGC.

Georgia ChanningHugging Face
Lindley DardenUniversity of Maryland
Oishi DebOxford University
Abigail DjossouUniversity of Toronto
Nikolas KalavrosNYU
Andriy KryshtafovychUC Davis
Jeff LamHong Kong University
John MoultUniversity of Maryland
Jan PedersenBright Minds
Emma ScharfmannHugging Face
Gustavo StolovitzkyNYU
Yuchen ZhouBEACON/Conscience

References

Sources

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