Fig. 2From: May critical molecular cross-talk between indoleamine 2,3-dioxygenase (IDO) and arginase during human aging be targets for immunosenescence control?A Elevations in arginase activity, evidenced by the proportions of ornithine to age-normalized arginine [Orn/(Arg/Age)] (Y-Axis), were significantly and positively correlated to IDO activity (X-Axis). B The molar levels of spermidine (Y-Axis) were significantly correlated to increases in IDO activity (X-Axis)Back to article page