MAOA and obesity due to melanocortin 4 receptor deficiency: Additionally, NAC suppressed the expression of key obesity-related proteins, including fatty acid binding protein 4 (FABP4), monoamine oxidase A (MAOA), heat shock protein 70 (HSP70), aminoacylase-1 (ACY-1), and transketolase (TKT) in 3T3-L1 cells [92].