SF3B1 and B-cell chronic lymphocytic leukemia: For instance, stereotyped subset #2 exhibits a 45–50% incidence of SF3B1 mutations as opposed to only 5–10% in generic CLL cohorts (122, 123); moreover, stereotyped subset #8 (IGHV4-39/IGKV1(D)-39), the CLL subgroup with the highest risk for Richter's transformation amongst all CLL (124), exhibits a ~60% incidence of trisomy 12 as opposed to only ~15% in generic CLL cohorts (120).