Iron deficiency increases dietary absorption of Pb2+ and other toxic metals such as cadmium (Cd) through the upregulation of divalent metal transporter 1 (DMT1), while essential trace elements such as Ca, iron (Fe), and zinc (Zn) appear to compete with Pb2+ ions for gastrointestinal (GI) absorption. The gene discussed is SLC11A2; the disease is Iron deficiency anemia.