MEN1 and lipoma: Studies in mice have revealed that Menin interacts with the LLXXL domain on peroxisome proliferator-activated receptor (PPARα/γ) and regulates gene expression by binding to the peroxisome proliferators response element (PPRE) on the target gene, playing an essential role in adipocyte differentiation, fatty acid oxidation, de novo fat synthesis, and lipoma development [11, 14, 39].