Positive and negative regulation of deltaN-p63 promoter activity by p53 and deltaN-p63-alpha contributes to differential regulation of p53 target genes.

Mammary epithelial regeneration implies the existence of cellular progenitors with retained replicative capacity, prolonged lifespan and developmental potency. Evidence exists that deltaN-p63 isoforms preserve these features by modulating p53 activity in basal epithelia. deltaN-p63 mRNA levels decline at the onset of differentiation suggesting that its transcriptional regulation may contribute to the initiation of differentiation.