We also examined the cell surface binding of mAb2 on the primary murine MLL-ENL/Flt3ITD/+ bone marrow cells which showed poor and non-specific staining with an isotype control antibody, while mAb2 staining produced punctate, cell surface specific clusters (Extended Data Figure 2I) as seen on the human AML cell lines. This evidence concerns the gene KMT2A and acute myeloid leukemia.