MMP2 and pituitary gland adenoma: The function of the ECM is affected by the dynamic balance between MMPs (matrix metalloproteinase) and TIMPs (tissue inhibitor of matrix metalloproteinases), and a systematic review and meta‐analysis involving 1320 patients with pituitary adenomas found elevated expression levels of MMP‐9 and MMP‐2 in patients with invasive pituitary adenomas, but no difference in TIMPs.57