GSTM1 and chronic kidney disease: Furthermore, the NDD-CKD group showed more elevated serum ferritin, urea, creatinine levels, serum levels of iPTH, sFas, C-reactive protein, IL-6, IFN-γ, sFas/eGFR, EPO/Hb ratio and lower eGFR, Hb, hematocrit (Ht) concentration, platelets, and serum albumin than healthy individuals (Table 1).