Several of these cytokines, such as TNF-α and IFN-γ play a protective role in malaria by arresting parasite replication and enhancing parasite killing (Clark et al., 1990), but also contribute to anemia by inhibiting erythropoiesis (Miller et al., 1989; Dufour et al., 2003). The gene discussed is TNF; the disease is anemia (phenotype).