IL6 and anemia: Since MIF (i) contributes to the accumulation of WBC (including phagocytes; Fig 1F) in tissues that are potentially involved in erythrophagocytosis and extramedullary erythropoiesis, and (ii) stimulates the production of the erythroid lineage development-blocking cytokine IL-6 [30] in the two main erythropoietic tissues (bone marrow, spleen; Fig 2B and 2C), we investigated MIF’s role in anemia development during T. congolense infection.