Iron deficiency in the intestinal epithelial cells leads to the upregulation of the ATP7A gene and iron-homeostasis related genes: the cell surface ferrireductase gene Dtcyb, the iron ion transporter gene DMT1 and the basolateral iron exporter ferroportin gene (FPN) (Xie and Collins, 2011, Xie and Collins, 2013). The gene discussed is SLC40A1; the disease is nutritional disorder.