The experiment was performed on samples collected prior to treatment interventions from 50 children representing two extremes of clinical malaria phenotypes: mild malarial anemia (non-SMA; Hb levels of 8.1–12.4 g/dL; n = 38, average Hb = 9.3 g/dL) and severe malarial anemia (SMA; Hb levels of 4.1–5.9 g/dL; n = 12, average Hb = 5.3 g/dL). Here, GSTM1 is linked to anemia (phenotype).