KMT2A and acute lymphoblastic leukemia: Given that KMT2A-R ALL is often a monoallelic balanced translocation with wild-type KMT2A and AFF1 still present in the cells, we then analyzed a ChIP-Seq data set that used human KMT2A-R leukemia cells generated via overexpression of a KMT2A-Aff1-flag construct [36].