KMT2A and lymphoid leukemia: With the exception of EAF1/2 and P-TEFb (a heterodimer of CDK9 and CyclinT1/T2), all other SEC components frequently fuse with N-terminus of Mixed Lineage Leukemia (MLL) to form MLL fusion proteins that, in conjunction with wild type MLL, gives rise to pediatric acute form of both myeloid and lymphoid leukemia through aberrant transcriptional misregulation of HOX cluster genes during hematopoiesis7.