SORT1 and obesity due to melanocortin 4 receptor deficiency: Of the several other mouse models with altered hepatic sortilin expression that they studied (ob/ob, diet-induced obesity, L1B6Ldlr−/−), this was the only one that had differential effects on TG and apoB-100 secretion, leading the authors to speculate that the increased secretion of relatively TG-deficient particles was due to the modulation of other pathways involving mTORC1.