Stack entered the model lineage

Why this model matters

State is Arc Institute's first virtual-cell model: given a starting transcriptome and a perturbation (drug, gene edit or cytokine), it predicts how gene expression will shift. Trained on ~170M observational and 100M+ perturbational cells across 70 contexts, it pairs a State Embedding module with a State Transition transformer. Its 2026 successor, Stack, learns cell biology in-context to generalize to unseen conditions.

Current evidence boundary

• Performance depends on the evaluation dataset and operating conditions.
• Task-specific benchmark results should not be compared across unlike domains.
• Outputs require task-specific scientific and experimental validation.