For instance, in Wilson's disease (WD), a genetic disease resulting from pathogenic variants of the ATP7B copper transporter, serum samples exhibit elevation of non-ceruloplasmin-bound copper while total serum copper levels are not significantly affected.19 Acquiring knowledge to track both tissue and extracellular copper fluxes in cases such as this would have diagnostic potential and will shed light on the systemic manifestations of the disease. The gene discussed is CP; the disease is Wilson disease.