However, PRKAR2B mRNA levels have been found to be significantly lower in adipose tissue of obese patients than in that of nonobese patients and to be negatively correlated with BMI, waist circumference, and insulin levels, consistent with the hypothesis that the expression and activation of PRKAR2B might contribute to the different lipolytic response to β-adrenergic activation in obesity (12). Here, PRKAR2B is linked to obesity due to melanocortin 4 receptor deficiency.