TLR9 and obesity due to melanocortin 4 receptor deficiency: Therefore, on the basis of constructing high-fat diet-induced obese rat model, studying the human omental adipose tissue, and culturing adipocytes in vitro, our research intended to explore the molecular mechanism of the inhibition effect of TLR9/KLF4 on FFA-induced inflammatory response of adipocytes, which can help to elucidate the molecular mechanism of obesity initiating inflammation.