Of note, we observed not only a high ibrutinib responsiveness in the parental U-CLL Hg3 cell line—well in line with the clinical observation of high ibrutinib sensitivity in U-CLL—but also a markedly decreased sensitivity in the SLAMF1 and SLAMF7 overexpressing Hg3 sublines (Supplementary Fig. S4D). The gene discussed is SLAMF1; the disease is B-cell chronic lymphocytic leukemia.