The KMT2A gene, better known as MLL (mixed lineage or myeloid/lymphoid leukemia) encodes a lysine (K)-specific histone methyltransferase 2A, which functions as an epigenetic regulator of transcription (Daniel and Nussenzweig, 2012; Takeda et al., 2013). Here, KMT2A is linked to lymphoid leukemia.