ATIC and adenoma: In a study encompassing 100 individuals equally distributed as healthy individuals, patients with early/late adenomas and patients with adenocarcinomas from stage-I to stage-IV, liquid chromatography–tandem mass spectrometry of serum extracellular vesicles identified six proteins, GCLM (involved in glutathione synthesis), KEL (endopeptidase), APOF (apolipoprotein F), CFB (complement factor B), PDE5A (cGMP-specific phosphodiesterase) and ATIC (purine biosynthetic pathway), that distinguished healthy control, early neoplasia and advanced neoplasia patients from each other [153].