p63 is the primordial member of the p53 family that acts in a conserved process of monitoring the integrity of the female germline, whereas the functions of p53 are restricted to vertebrate somatic cells for tumor suppression. p63 protein plays an important role in the development and maintenance of stratified epithelial tissues. p63 is critical for maintaining the progenitor-cell populations that are necessary to sustain epithelial development and morphogenesis. Mutations in p63 are associated with ectodermal dysplasia, cleft lip/palate syndrome 3 (EEC3) and split-hand/foot malformation 4 (SHFM4).