Introduction:Glycomacropeptide (GMP) present in cheese whey is a C-terminal hydrophilic glycopeptide released from k-casein by the action of chymosin.In recent years,there has been increasing interest in exploiting GMP as nutraceutical peptide for human health benefit.Our previous study demonstrated that pepsin digestion of GMP enhanced the degree of cell proliferation and phagocytic activities of human monocyte and sialic-rich GMP fractions showed an increased response.