We isolated primary leukemic B cells from PB samples obtained from patients (n = 11) (Supplementary Table 2; Hallek et al., 2008) with CLL and from healthy donors (n = 6) for determining the endogenous HS1 localization at the increased resolution of the 3D-STED imaging. This evidence concerns the gene HCLS1 and B-cell chronic lymphocytic leukemia.