However, in a malaria endemic region such as Nigeria, the real effect of such interventions may be masked due to the confounding effect of malaria on serum Hb: Malaria infection initiates hemolysis of both parasitized and nonparasitized RBCs, which leads to a depletion of Hb concentrations, thus leading to anemia (53). Here, GSTM1 is linked to anemia (phenotype).