Current knowledge proposes iron deficiency or hypoxia to act via nuclear HIF-1/FIF-2a/HIF-b, triggering a transcriptional induction of Tfrc together with Hmox1, Slc11a2 (DMT1), Slc40a1 (FPN1), Epo, and Cp [72]. The gene discussed is EPO; the disease is Iron deficiency anemia.