Over the last years, it has been discovered that somatic missense mutations in several PKMTs such as EZH2, GLP, NSD2, MLL3, and MLL1 occur in cancer tissues and promote carcinogenesis by altering the catalytic activity or overall properties of the PKMT, including their activity, product pattern or substrate specificity (Kudithipudi and Jeltsch, 2014; Weirich et al., 2015; Yap et al., 2011). Here, KMT2A is linked to cancer.