TP53 and neoplasm: Lastly, activated SETDB1 interaction with ΔNp63 in BCs, a p63 isoform without an N-terminal transactivation domain, redirects SETDB1 to specific tumor suppressor genes, such as p53, Apolipoprotein E (APOE) and Homeobox A (HoxA), causing chromatin changes and gene silencing [87].