SF3B1 and B-cell chronic lymphocytic leukemia: A high frequency of SF3B1 gene mutations was noted for CLL#3 (9/22, 41%) and CLL#5 (8/21, 38%), compared to that in other subgroups: CLL#1 (3/35, 8%), CLL#6 (4/21, 20%), CLL#99 (3/22, 13.6%), and CLL#7H (3/10, 30%).