TNF and anemia: In COVID-19 patients, the overexpression of interleukin (IL)-1, IL-6, interferon-γ and tumor necrosis factor (TNF)-α profoundly affect iron metabolism and erythropoiesis, leading to shortened erythrocyte lifespan, segregation of circulating iron into macrophages in the bone marrow, liver and spleen and shifting blood cell production towards myelopoiesis at the expense of erythropoiesis7 and finally leading to anemia.