In univariate analysis including both non-CKD and CKD patients, Cat-S was inversely correlated to eGFR (rho (r) = −0.244, p < 0.001, Fig. 2A) and was positively associated with creatinine (r = 0.167, p = 0.001), BUN (r = 0.166, p = 0.001), cystatin C (r = 0.231, p < 0.001) as well as both sTNFR1 (r = 0.304, p < 0.001, Fig. 2B) and sTNFR2 (r = 0.178, p < 0.001, Fig. 2C). Here, CST3 is linked to chronic kidney disease.