Sublethally irradiated mice (Ly5.1) transplanted with bone marrow cells (from Ly5.2 mice) harboring a C-terminal-truncating Asxl1 mutation (derived from the mutated genes of 1934dupG;G646WfsX12 and 1900–1922del;E635RfsX15 of patients with MDS) exhibited multilineage myeloid dysplasia and occasional progression to acute leukemia. This evidence concerns the gene ASXL1 and myelodysplastic syndrome.