A2M has been successfully included in multivariate analyses of fibrosis biomarkers, mostly combined with ApoA1 and haptoglobin, for the surveillance of chronic viral hepatitis C and B, alcoholic liver disease, and various metabolic liver diseases including dyslipidemia, NAFLD with and without T2DM [31,32], sole T2DM [27,28,32,33,34,35,36,37], steatosis [33], and non-alcoholic steatohepatitis (NASH) [34,35,36,37], and has been associated with severe obesity [39], patients with bariatric surgery [39], obstructive sleep apnea [40], and the general population [31]. The gene discussed is APOA1; the disease is obesity due to melanocortin 4 receptor deficiency.