Using PAM, between adenoma and normal biopsy samples, 20 classifiers were identified, including overexpressed cadherin 3, KIAA1199, forkhead box Q1 and downregulated carbonic anhydrase 7, glucagon, somatostatin, Spi-B transcription factor, claudin 8, bestrophin 4, peptide YY (sensitivity: 100%, specificity: 100%) (Table 1). The gene discussed is CLDN8; the disease is adenoma.