SLC39A4 and acrodermatitis enteropathica: One of those genetic defects is associated with mutations of the intestinal Zn2+-specific transporter Slc39a4/Zip4 [12, 13], which is responsible for Zn2+ absorption in the small intestine and when mutated leads to a rare, autosomal recessive disease called acrodermatitis enteropathica (AEZ) (OMIM number 201100).