This is because KMT2A-r ALL develops into LS far more often than ALL with other translocations2,3, and KMT2A::AFF1 is the most common fusion among KMT2A-r ALL6,7; therefore, the MDSC-like features should also be assessed in LS AML cases with other genetic backgrounds. Here, AFF1 is linked to acute lymphoblastic leukemia.