UNC0646 is a potent and selective inhibitor of protein lysine methyltransferases G9a and GLP activities in vitro (IC₅₀s = 6 and 15 nM, respectively) ; inhibits G9a/GLP-mediated dimethylation of histone 3 on lysine 9 in MDA-MB-231 cells (IC₅₀ = 26 nM). It is highly selective for G9a/GLP over several other protein lysine and arginine methyltransferases.UNC0646 potently inhibits G9a/GLP activity in a variety of cancer cell lines as well as in the human fetal lung IMR-90 line.