PCNA and acute promyelocytic leukemia: For the DDD category for the Minus subclone, there were 4 genes, all in our list of genes of special interest to the study of neutrophil differentiation in response to drug treatments for APL: C/EBP-gamma, which may cooperate with FOS to bind PRE-I enhancer elements; c-Myc, known to be down-regulated by retinoic acid; PCNA, and PPARBP (PPAR binding protein), which, along with TFIID, can activate the SP1 transcription factor, interact with thyroid hormone receptor, or function with p53 in apoptosis.