The increased circulating SAA levels observed in individuals with obesity are highly correlated with body mass index (BMI), body weight, adiposity, and SAA1 and SAA2 mRNA expression in white adipose tissue (WAT) (11, 96), and are not related to hepatic SAA1 or SAA2 expression (9, 97, 98, 103). Here, SAA1 is linked to obesity due to melanocortin 4 receptor deficiency.