PPARG and obesity due to melanocortin 4 receptor deficiency: In a study by Darwish et al., which examines the correlation of PPARγ with obesity, it was shown that the mRNA expression of PPARγ was the most abundant in the serum of obese patients and statistically demonstrated strong positive correlation with the obesity variables, including the BMI, waist circumference and waist–hip ratio of obese patients [81].