Notably, both MCPH3/Cdk5rap2 and MCPH5/Aspm-null mice exhibited microcephaly at birth, and the degrees of reduction of the brain sizes of those mutant mice [25], [41] are comparable to our Zfp568fx/fx;Nes-cre mice (Figure 5C). Here, CDK5RAP2 is linked to microcephaly.