To test whether upregulation of p53 led to the cell death and microcephaly, Arglu1 cKO mice (Emx1Cre/+-Arglu1fl/fl) were crossed with the whole-body p53 KO mice (p53−/−) to generate the Emx1Cre/+-Arglu1fl/fl;p53−/− mice in which p53 and Arglu1 were simultaneously removed. The gene discussed is ARGLU1; the disease is microcephaly.