MTOR and obesity due to melanocortin 4 receptor deficiency: Interestingly, Nucb2/nesfatin-1 expression in gastric mucosa co-localizes with the mTOR signaling molecule pS6k1 and a matching relationship between gastric nesfatin-1 production and mTOR signaling occurs at the gastric level under alterations in nutritional status and also in pathological processes such as obesity.