SF3B1 and chronic myelomonocytic leukemia: In this respect, large-scale genomic studies indicate that mutations of the Hsh155/SF3B1 protein recur in hematologic malignancies (i.e., myelodysplastic syndromes (MDS) [13], chronic lymphocytic leukemia [14], and chronic myelomonocytic leukemia [15], and less commonly in solid tumors [7]).