CDKN1A and skin cancer: Because the development of UVB-induced skin cancer often entails early oncogenic events involving the mutation of a single p53 allele and the escape from UVB-induced apoptosis, we examined whether a dominant inhibitory mutation in a single p53 allele (p53+/R172H) could greatly impair UVB-induced lincRNA-p21 transcript levels and apoptosis when compared with loss-of-function mutation involving deletion of a single p53 allele (p53+/−).