CXCL12 and pituitary gland adenoma: Interestingly, GH4C1 rat pituitary adenoma cell line expresses CXCR4 but not CXCL12, thus it was proposed as a suitable model to characterize the molecular pathways regulated by this receptor in pituitary adenomas, without the interference of the endogenously released CK [127, 211, 212].