PLOD1 and adenoma: According to the postoperative histopathological testing, there were 22 null cell adenomas, 12 silent adenomas (including 1 PRL-positive, 1 GH-positive, 1 ATCH-positive, 5 FSH/LH-positive, 2 TSH-positive, and 4 plurihormonal-positive) among non-functioning adenomas.