KMT2A and acute lymphoblastic leukemia: Overall, next generation sequencing studies have revealed a low incidence of somatic mutations in ALL infants with KMT2A rearrangements [156,157], although these include mutations in tyrosine kinase PI3K-RAS signaling pathways and to a lesser extent in FLT3, as well as abnormal DNA methylation patterns [138,139,158,159,160,161].