Genes such as p16 [76,77,78], CDH1 [69,79], p18INK4C [80], NDRG2 [81], GADD45b [82], MEN1 [83], the hTERT promoter [84], and the STAT3 promoter [85] showed no association with clinical differences between pituitary adenomas and normal tissue. Here, CDH1 is linked to pituitary gland adenoma.