PMAIP1 and melanoma: In melanoma tissue extracts, P53 target genes involved in apoptosis were down-regulated compared to melanocytes; the exception being genes for FLIP (inhibitor of Caspase 8), PMAIP1 (Noxa, BH3 pro-apoptotic protein) and the ATF3 transcription factor (transcript variant 4 or deltaZip2) which can counteract transcriptional repression by full-length ATF3 [33].