PTTG1 and pituitary gland adenoma: Accordingly, PTTG1 is highly expressed in endocrine and non-endocrine malignancies such as pituitary adenoma, astrocytoma, thyroid cancer, breast and ovarian cancer, renal cell carcinoma, lung cancer, colorectal carcinoma, HCC, and leukemia [10,16,17,18,19,20].