SF3B1 and chronic myelomonocytic leukemia: On the other hand, ASXL1 and SRSF2 mutations are infrequent in SF3B1 mutant CMML, which may suggest that SF3B1 mutant CMML differs clearly from CMML without SF3B1 mutations and this specific biological profile translates into a distinct phenotype and survival rate (12, 13).