RETN and obesity due to melanocortin 4 receptor deficiency: Additionally, plasma proteome analysis showed that chitosan increases the level of adiponectin and decreases the levels of obesity-related proteins, such as resistin, retinol-binding protein 4, TNF-α and interleukin-6 (IL-6), contributing to the anti-diabetic and anti-obesity potentials in ob/ob mice [10].