PPARG and obesity due to melanocortin 4 receptor deficiency: Several PPARγ antagonists (such as SR1664) have also yielded therapeutic effects in the treatment of obesity with better therapeutic index comparing with PPARγ agonists by overcoming thiazolidinedione drugs’ undesirable side effects, such as heart failure, and fluid retention with increased risk of weight gain, loss of bone mineral density [27,28].