Mutations in the HEAT domains of the core splicing factor 3 B1 (SF3B1) are common in several malignancies including myelodysplastic syndrome (MDS) (1,2), chronic lymphocytic leukemia (CLL) (3), uveal melanoma (4) and cancers of breast (5), liver (6) and pancreas (7). Here, SF3B1 is linked to B-cell chronic lymphocytic leukemia.