GSTM1 and chronic kidney disease: In subgroup analysis among placebo-controlled trials stratified by dialysis status and follow-up duration, beneficial effect on Hb CFB associated with HIF-PHIs treatment strengthened in NDD-CKD patients (MD, 1.21; 95% CI, 0.82 to 1.60; I2 = 94.35%) and in trials with short follow-up (<20 weeks) (MD, 1.40; 95% CI, 1.06 to 1.75; I2 = 89.51%), while such beneficial effect diminished in DD-CKD subjects and trials with long term follow-up (≥ 20 weeks).