CP and Wilson disease: To improve diagnosis as well as treatment monitoring of WD, several additional copper metabolism biomarkers were studied and still are under investigation, such as non-ceruloplasmin bound copper (NCC), exchangeable copper (CuEXC), relative exchange copper (REC), albumin-copper (Cu-ALB), directly measured non-ceruloplasmin bound copper (dNCC), and labile bound copper (LBC) [17,37].