This blockade enhances the body’s antitumor immune response.[15] In the case of GBC, the positivity rate of PD-L1 in tumor cells (with a cutoff value set at ≥ 1%) has varied between 14.7% and 23% and has been linked to a poor prognosis.[16] Additionally, The expression levels of PD-1 in advanced biliary tract malignant tumors were not significantly associated with the efficacy of different ICIs or PFS. Here, PDCD1 is linked to biliary tract cancer.