July 9, 2026
A 20-year-old brain-size gene, a whole-brain CRISPR atlas, and the cell type nobody was looking at
Two decades ago, Chenn & Walsh showed β-catenin sets cortical size; later work established APC as its Wnt-pathway antagonist. GWAS caught the pathway — but never these two genes individually, and never with a cell type. The first genome-scale, whole-brain, in-vivo Perturb-seq atlas quietly supplies the missing piece, in a structure and life-stage the classic work never reached.