We observed three prevalently used IGHV subgroups, IGHV1 (n = 45, 27.3%), IGHV11 (n = 81, 49.1%) and IGHV12 (n = 19, 11.5%), accounting for 87.9% of all CLL clones (n = 166) (Fig. 1B). Here, IGHV1-2 is linked to B-cell chronic lymphocytic leukemia.