IL-6 was found to be elevated in obesity and type 2 diabetes mellitus patients, while Circulating ZAG levels in the serum and adipose tissue of obese patients and obese mice are notably lower in compare to normal subjects and ZAG were found to be oppositely associated with insulin resistance in type 2 diabetes mellites patients26–29. This evidence concerns the gene IL6 and obesity due to melanocortin 4 receptor deficiency.