GSTM1 and chronic kidney disease: This is further supported by the Chronic Kidney Disease Outcomes and Practice Patterns (CKDopps) study, a prospective cohort study of patients with NDD-CKD-related anemia from 2013 to 2018: among French patients with Hb <10 g/dL, 34% were not prescribed ESA or iron therapy in the 3 months following Hb measurement [15].