NNMT and obesity due to melanocortin 4 receptor deficiency: Since NNMT expression is directly determined by the NNMT gene, in our previous works, nineteen SNPs in the NNMT DNA sequence were selected as tagSNPs using Haploview software (Haploview 4.2) to observe the association between NNMT gene polymorphisms and obesity [29] and hyperlipidemia [30].