In humans, missense mutations in SLC39A4 affecting the ZIP4 transmembrane domains have been associated with Acrodermatitis enteropathica (AE), a genetic condition characterized by concurrent manifestation of diarrhea, dermatitis, alopecia, skin lesions, growth retardation, impaired wound healing, and male hypogonadism together with low sperm count (Maverakis et al., 2007) due to defective cellular zinc uptake. Here, SLC39A4 is linked to skin disorder.