Fig 9 showed that at the fifth week, there was a small amount of fibroplasia and at the 16th week, a large amount of fibroplasia can be easily observed. The CCA data was referred to Sprague-Dawley (SD) rats fed thioacetamide (TAA) water for 18 weeks. Real-time quantitative polymerase chain reaction showed that not only CHST4 but also CK19 were highly expressed in tumor tissues with statistical significance, verifying the role of CHST4 as the core gene of CCA (Fig 10, S2 Data). The gene discussed is KRT19; the disease is cholangiocarcinoma.