“…Various types of cytokines, such as IL-6 or tumor necrosis factor-␣, are known to be present in the bloodstream after exercise (6,38). IL-2, IL-4, TGF-, and IFN-␥, however, are least likely to be induced during or after acute exercise (18,19,27,35). Thus it is reasonable to suppose that these cytokines may not affect CXCR4 expression.…”