The CACC group was significantly younger at diagnosis of CCA (median, 65 years vs. 62 years, p = 0.018), had higher male to female ratio (83.2 vs. 61.8%, p < 0.001), more frequent elevated serum CEA levels (>5 U/ml), and included more patients living in CS-endemic areas (46.3 vs. 25.4%, p = 0.014) than the non-CACC group. The gene discussed is CEACAM5; the disease is cholangiocarcinoma.