ADRB3 and obesity due to melanocortin 4 receptor deficiency: Although few researchers have investigated the relationship of the ADRB3 gene and its role in susceptibility to obesity, only three studies on methylation were found in the literature consulted, being the first performed with methylation of ADRB3 gene in severely obese men [23], the second with methylation in VAT in obese and slim individuals [9], and the third with methylation in overweight and obese adult women [18].