PerturbAI emerged from stealth with a public in‑vivo Perturb‑seq atlas mapping gene function across 8 million mouse brain cells. The San Francisco startup, backed by a pre‑seed round and partnerships with 10x Genomics, NVIDIA and the Allen Institute, said the dataset links thousands of genetic perturbations to cell‑type and circuit‑level outcomes and is available for public use. PerturbAI’s approach measures gene function in intact tissue to capture contextual effects that differ by cell type and brain region—a critical advance over cell‑culture perturbation datasets. The company positions the atlas as both a drug‑discovery resource and AI training substrate to accelerate causal modeling for therapeutics. A bioRxiv manuscript will accompany the dataset; PerturbAI said its platform will scale in‑vivo causal genomics for translational research and AI model development.