Increasing evidence shows that dipeptidyl aminopeptidase IV (DPP IV) is associated with cancer development and progression [27,28]; DPP4 is an adenosine deaminase complex protein, and was demonstrated to be upregulated in THCA, particularly in PTCa, and is associated with tumor aggression and poor prognoses [29,30,31]. This evidence concerns the gene DPP4 and pituitary adenocarcinoma.