Though GNB2 mutations were not identified in human MLL-AML (Fig. 3), Gnb2 mutation had a significant impact on poor prognosis in mouse MLL/AF9-AML, increased in clone size during the serial transplantation, and existed in other human hematological neoplasms [23]. Here, KMT2A is linked to hematopoietic and lymphoid system neoplasm.