As has been previously reported, CLL samples with mutated XPO1 invariably were found to use unmutated IgHV (72/72 cases, 100%; IgHV-U) in contrast to samples with wt XPO1, for which only 633 of the 1,068 evaluable cases (59%) used unmutated IgHV (Additional file 1: Fig. S1A). Here, XPO1 is linked to B-cell chronic lymphocytic leukemia.