Although several Wilson disease mutations result in defects in ATP7B trafficking, ATP7B proteins with a G85V or G591D mutation were reported to have normal cellular localization (although this has been questioned (de Bie et al. 2007)), but they appear to be expressed at lower levels (de Bie et al. 2007; van den Berghe et al. 2009) and have impaired interactions with Atox1 in model systems (Hamza et al. 1999). This evidence concerns the gene ATP7B and Wilson disease.