CD27 and cancer: In summary, a number of immunotherapies outside of conventional ICI have been or are being explored in BTCs, including dual ICI and TGF-beta trapping using bintrafusp alfa, immunostimulatory agonists targeting CD27 or CD40, anti-DKK1 therapeutics that target Wnt signaling, cancer vaccines, and adoptive cell therapies including CAR-T and allogeneic NK cells.