SF3B1 mutations are associated with advanced stages, male sex, high leukocyte counts, elevated B2 microglobulin levels, high CD38 expression, U-CLL subgroup, intermediate CLL epigenetic subgroup, stereotyped BCR subset 2 and R110-mutated IGLV3-21 subgroup, as well as with 11q deletion and fludarabine resistance [11,13,152,153,154,155]. The gene discussed is BCR; the disease is B-cell chronic lymphocytic leukemia.