The cancer-associated mutations targeted genes that are recurrently mutated in KMT2A-r ALL, including PI3K/RAS-genes, TP53 and PAX5, in line with identified mutations likely being biologically relevant.5,27 By contrast, the 20 genes that lacked cancer-associated mutations are typically not mutated in KMT2A-r leukemia. This evidence concerns the gene PAX5 and acute lymphoblastic leukemia.