Consequently, the cKO-Cdkn1c-MADM-7 mice exhibit very strong microcephaly (Fig. 3o–q), similar to Cdkn1c-MADM-7 mice with maternal deletion (Fig. 3c–e), and slightly more severe than with paternal deletion (Fig. 3i–k). This evidence concerns the gene CDKN1C and microcephaly.