Studies found that 18beta-glycyrrhetinic acid had significantly antitumor effects on pituitary adenomas because this drug activated mitochondria-mediated ROS-mitogen-activated protein kinase (MAPK) pathways to induce cell apoptosis in pituitary adenomas, and that these activating effects were attenuated in pituitary adenomas by pretreatment with N-acetyl-L-cysteine, a ROS inhibitor (29). This evidence concerns the gene WNK2 and pituitary gland adenoma.