The failure of CLL cell migration into the lymphoid tissues in Lyn−/− recipients could be excluded, because CLL cells could efficiently home to the spleen and bone marrow of both Lynwt/wt and Lyn−/− recipients in an in vivo short-term homing assay (Supplementary Fig. 1b). The gene discussed is LYN; the disease is B-cell chronic lymphocytic leukemia.