To evaluate whether TFF2 could be used as a serum marker for PC, the levels of TFF2 in serum samples from 15 patients with PC, 15 patients with periampullary adenocarcinoma, including 6 CCA, 6 ampullary carcinoma, and 3 duodenal adenocarcinoma patients, and 15 healthy controls were determined by a quantitative ELISA assay. The gene discussed is TFF2; the disease is pachyonychia congenita.