GSTP1 and obesity due to melanocortin 4 receptor deficiency: We found no significant interaction between BC and GSTP1 or GSTT1 genotypes; between SO4 and any genetic variant; for any of the genetic variants and either BC or SO4 on the change in LINE-1; or with any of the host characteristics evaluated as potential effect measure modifiers (i.e., current smoking, obesity, or use of antihypertensive medications) for either BC or SO4.