TP53 and skin cancer: In sun-exposed areas of the human skin, p53 plays an important role in skin cancer prevention through its regulation of keratinocyte cell cycle arrest and apoptosis in response to UVB radiation-induced DNA damage.17, 19, 20, 21, 22, 23, 24, 40 These p53-regulated responses serve to prevent UVB-induced mutagenesis by producing cell cycle arrest to allow time for DNA repair and by triggering apoptotic death of DNA-damaged keratinocytes.