Especially in field-based conditions, there is an urgent need for simple but reliable devices for the simultaneous, inexpensive assessment of Hb, malaria, parasitic infections, ferritin, CRP/AGP, and/or hepcidin, especially those that could provide a combination of biomarkers to obtain a diagnosis of the cause of anemia, such as the simultaneous detection/quantification of anemia, malaria, and inflammation-adjusted iron deficiency. The gene discussed is GSTM1; the disease is anemia (phenotype).