ADRB2 and neoplasm: EZH2 is thought to promote tumorigenesis via epigenetic silencing of a group of tumor suppressor genes, including ADRB2, CDH1, PSP94, and DAB2IP. Overexpression of EZH2 trimethylates H3K27 and thus inhibits gene expression, particularly among tumor suppression genes (Figure 2). DAB2IP is a novel GTPase-activating protein for modulating the Ras-mediated signal pathway and tumor necrosis factor- (TNF-) associated apoptosis.