For example, it has been extensively shown the crucial role that MLL3/MLL4/COMPASS-like family of histone H3 lysine 4 (H3K4) monomethyltransfereases have in cancer [21,22] and also the role that TERT promoter mutations leading to upregulation of telomerase expression observed in human cancer [23,24]. The gene discussed is KMT2C; the disease is cancer.