PFKFB4 and obesity due to melanocortin 4 receptor deficiency: In human adipocyte models, quercetin significantly downregulated adipokines (i.e., Angiopoietin Like 4 (ANGPTL4) and Serpin Family E Member 1(SERPINE1, previously known as PAI-1)) and glycolysis-associated enzymes (i.e., Enolase 2, gamma neuronal (ENO2) and 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 4 (PFKFB4)), which are closely related to obesity [56].