Table 6 shows the relationship between pathological features and expression of IDO1, FASLG and NT5E in CCA patients in the cBioPortal database. Chi-squared tests were used to compare the clinicopathological data. IDO1 expression in CCA patients was associated with neoplasm disease stages II and III (p = 1.874 × 10−3). Patients with altered IDO1 expression was associated with a presence of a risk factors for HCC, including smoking and hepatitis B (p = 0.012). Here, IDO1 is linked to hepatitis B virus infection.