Anorexia nervosa patients often have hypercholesterolemia.20 Hyperadiponectinemia is known to occur in anorexic patients,21 and may be related to increased cholesterol synthesis.22 To account for impact of altered cholesterol levels on 4βOHC concentration, we consider 4βOHC/C ratio to be a more appropriate CYP3A biomarker in this study population. The gene discussed is CYP3A4; the disease is familial hypercholesterolemia.