NNMT and obesity due to melanocortin 4 receptor deficiency: NNMT expression is increased in several disease pathologies, including neurodegenerative diseases such as Alzheimer’s [38] and Parkinson’s disease [39,40], hepatic cirrhosis [41], atherosclerosis [42], pulmonary hypertension [43], acute hepatitis [44], fatty liver disease [45], obesity and metabolic syndrome [46,47], peripheral occlusive arterial disease [48] and chronic obstructive pulmonary disease [49].