This was due to secretion by CD4+ T cells of pro-tumor Th2 cytokines (i.e., mainly IL-10 and IL-13), possibly with activation of CD4+ NKT and myeloid suppressive cells (60, 61), and tumor-derived CCL17 that in turn recruited Tregs already described to have a pro-metastatic role in breast cancer (28). Here, CD4 is linked to breast cancer.