Alongside S100A8/A9, a number of endogenous TLR-4 ligands including gut-derived LPS, HMGB1, and modified LDL are elevated in the plasma and adipose tissue in obesity and may contribute to ATM priming to produce IL-1β (Erridge, 2010). This evidence concerns the gene TLR4 and obesity due to melanocortin 4 receptor deficiency.