PNPLA2 and obesity due to melanocortin 4 receptor deficiency: An in vitro study showed that kaempferol inhibited the adipogenic differentiation of 3T3-L1 cells by inhibiting the expression of Cebpa, a gene regulating adipocyte differentiation, and reduced lipid accumulation in mature adipocytes by promoting the transcription of lipid metabolism-related genes Pnpla2 and Lipe, thereby achieving the purpose of treating obesity [43].