Bacterial lipopolysaccharide9,11 and peptidoglycan32 represent two classic examples accounting for obesity-related insulin resistance during metabolic endotoxemia, by activating Toll-like receptor 4 (TLR4) and nucleotide-binding oligomerization domain-containing (NOD) proteins (NOD133–35 and NOD236,37), respectively. Here, TLR4 is linked to Obesity.