CST3 and Abnormal renal physiology: Taking into account the differences in the present study between serum creatinine/eGFR(crea) and serum cystatin C/eGFR(cys) and the assumption that serum cystatin C or the eGFR(cys) are more sensitive and earlier markers of renal dysfunction or damage [16, 26, 34], one possible conclusion might be that serum cystatin C concentrations, eGFR(cys) and serum Ang-2 concentrations might be reacting sooner towards renal impairment with potential endothelial activation than serum creatinine concentrations.