TNF and obesity due to melanocortin 4 receptor deficiency: Given that FAM19A5 is expressed in human adipocytes and its mRNA expression and protein synthesis are downregulated by TNF-α (Tourniaire et al., 2013; Wang et al., 2018), it has been hypothesized that the production of FAM19A5 may be conditioned by cardio-metabolic disorders related to obesity in humans.