In the human cytoplasm, after the uptake of Cu ions (Ohrvik and Thiele 2014), the Cu chaperone Atox1 transports the metal to the membrane-bound ATP7A and ATP7B (Menke’s and Wilson disease proteins, respectively), two homologous P1B-type ATPases located in the trans-Golgi network. The gene discussed is ATOX1; the disease is Wilson disease.