CHD8 and Neurodevelopmental delay: Together, these perturbations embraced 35 ASD/NDD risk genes, including Chd8. Since the small number of cells for any given perturbation per cell type prevented differential expression analysis between gene-edited and normal cells, Jin et al. [59] calculated the effect size of each perturbation on correlated expression modules across cell types compared with cells infected with control vector (i.e., lentiviral vector expressing green fluorescence protein) (Figure 4D).