Research progress on immunotherapy targeting the tumor immune microenvironment for cholangiocarcinoma

Cholangiocarcinoma (CCA) is the second most common hepatobiliary cancer, and its incidence has increased significantly in recent years. CCA has poor prognosis owing to the limited diagnosis and treatment options. The tumor immune microenvironment (TIME), which comprises immune cells, cytokines, and chemokines, plays a significant role in cancer progression, the evasion of immune surveillance, and therapeutic responses. Immunotherapeutic strategies targeting the TIME offer the potential for the recognition and eradication of CCA. This review discusses the cellular and molecular components of the TIME in CCA and immunotherapeutic strategies targeting it.