SLC20A1 and growth hormone-secreting pituitary adenoma: Nonetheless, recent research has shown that decreased expression of SFRP2 is associated with the development of corticotrophic adenomas [171], while overexpression of Solute Carrier Family 20 Member 1 (SLC20A1), which may be linked to the Wnt pathway, has been associated with larger tumor size, invasive behavior, and tumor recurrence in somatotroph adenomas [172].