The involvements and therapeutic potential of targeting PMTs in human cancer were initially illustrated in MLL leukemia where the recruitments of DOT1L by MLL-AF10 (Okada et al., 2005) and PRMT1 by MLL-EEN (Cheung et al., 2007) were required for transcriptional deregulation and cellular transformation. The gene discussed is DOT1L; the disease is leukemia.