GSTM1 and chronic kidney disease: Randomized controlled trials, including CHOIR, CREATE, and the Normal Hematocrit Trial, demonstrated that targeting normal hemoglobin levels in CKD or hemodialysis patients could lead to adverse outcomes, prompting a shift toward lower Hb targets and increased use of RBC transfusions (Szczech et al., 2008; Besarab et al., 1998; Eckardt et al., 2009).