The current study has shed light on previously unexplored associations of cytokine concentrations (IL-4 and IFNγ, in particular) with parasitic infections, undernutrition, micronutrient deficiency, anaemia, clinical signs and symptoms, inflammatory markers and anaemia markers, as well as differences in risk factors such as socioeconomic status, location of the primary schools, shoe-wearing habit, housing quality, drinking water sources, latrine ownership and its location. The gene discussed is IFNG; the disease is anemia (phenotype).