Moreover, considering that primary CLL cells are roundish and small (about 5–7 micron), with the nucleus that occupies most of the intracellular space, and that we expect inter- and intra-patient heterogeneity, a single X,Y 2D-STED plane would give insufficient information to derive conclusions about the distribution of the HS1 protein from a single patient, and from different patients. The gene discussed is HCLS1; the disease is B-cell chronic lymphocytic leukemia.