Bone morphogenetic protein-4 (BMP-4) has been proposed as both an oncogene and a tumor suppressor gene in pituitary adenomas Reduced BMP-4 expression is associated with epigenetic changes, which are reversed in AtT-20 and GH3 cell lines incubated with the epidrugs zebualarine and TSA [120]. This evidence concerns the gene BMP4 and neoplasm.