FOXO1 and pituitary tumor: Additionally, PPARα, PGC-1α, and FOXO1 ligands linked to acetylcarnitine may participate in the signaling pathways of prolactinoma, while SREBP-1c, LXRα/β, PPARγ, HIF-1α, PPARα, PGC-1α, and FOXO1 are likely involved in the signaling of nonfunctional pituitary tumors (45).