SAA, a classical, acute-phase protein and a product of hepatocytes, could potentially respond to infection, injury and inflammation and also has the ability to regulate toll-like receptor 4 (TIR4) which is associated with obesity-induced insulin resistance (Odhah et al. 2018; Sandri et al. 2008; Shi et al. 2006; Tannock et al. 2018). The gene discussed is SAA1; the disease is obesity due to melanocortin 4 receptor deficiency.