High BCL-2 expression has also been identified in KMT2A-rearranged ALL [8–10], and the KMT2A-AFF1 fusion has been shown to upregulate BCL-2 expression by promoting DOT1L-mediated H3K79 methylation at the BCL-2 locus [10]. This evidence concerns the gene BCL2 and acute lymphoblastic leukemia.