STAT3 and obesity due to melanocortin 4 receptor deficiency: Oxidative hepatic environment in obesity models of NAFLD has been associated with increased STAT-1 and STAT-3 signaling and inactivated STAT-1 and STAT-3 phosphatase T cell protein tyrosine phosphate (TCPTP), promoting hepatic T cell recruitment, NASH, fibrosis and HCC.