Before treatment we found mutations in genes that are recurrently mutated in CLL, (ATM, BIRC3, CHD2, DDX3X, IRF4, ITPKB, KLHL6, MYD88, NOTCH1, NFKBIE, SF3B1, SPEN, TP53 and ZMYM3) in nine patients (69%) with a mean of one mutation per case (min–max: 0–4). Here, IRF4 is linked to B-cell chronic lymphocytic leukemia.