ASXL1 and acute myeloid leukemia: ASXL1 mutations are common in myeloid neoplasms, including MDS,44, 47 CMML,7, 9, 48 PMF44, 49 and AML,47, 50 with respective mutational frequencies ranging from 15 to 20, 40–50, 20–35 and 5–10%.20 In general, they are associated with an aggressive phenotype.48, 49, 50 In MDS, Bejar et al.51 identified ASXL1 mutations in 63 (14.4%) of 439 MDS patients and found these to be IPSS (International Prognostic Scoring System) independent predictors for shortened OS.