Significantly, lower protein content in WD patients was observed for CYP1A1 (U = 34; N = 27; p = 0.049), CYP1A2 (U = 27; N = 27; p = 0.019), CYP2C8 (U = 19; N = 27; p = 0.005), CYP2C9 (U = 25; N = 27; p = 0.014), CYP3A4 (U = 24; N = 27; p = 0.012) and CYP3A5 (U = 30; N = 27; p = 0.029). The gene discussed is CYP2C9; the disease is Wilson disease.