Additionally, within the CD4-cell compartment there were more Th1 (IFN-γ+), Th2 (IL-4+), and T regulatory (Treg) (FoxP3+) cells in CLL patients than in HCs (Fig. S6B), consistent with the documented memory T-cell expansion in CLL [9]. Here, CD4 is linked to B-cell chronic lymphocytic leukemia.