However, conditional deletion of p57 in radial precursor (Emx1+ cells) causes microcephaly due to p53-mediated apoptosis, in this case p57 exerts a cell-autonomous growth-promoting function by promoting survival of maturing cortical projection neurons (Laukoter et al., 2020), consistent with the NestinCre-driven phenotype previously observed (Matsumoto et al., 2011a). The gene discussed is CDKN1C; the disease is microcephaly.