In Dyx1c1, “constitutive,” complete KOs exhibit major neuroanatomical defects due to severe hydrocephalus resulting from ciliary motility abnormalities (Tarkar et al., 2013) but when Dyx1c1 was knocked out specifically in the neocortex during its development (using a forebrain‐specific mutant, Emx1‐Cre, that targets cortical neurons only), cortical lamination remained unaffected (Rendall et al., 2017). Here, DNAAF4 is linked to Hydrocephalus.