CD274 and cholangiocarcinoma: We examined integrin αvβ6 and PD-L1 expression in CCA cell lines and engineered T cells to express either fourth-generation CAR T cells targeting integrin αvβ6 (A20 CAR4 T cells) or fifth-generation CAR T cells with anti-PD-L1 scFv secretion (A20 CAR5 T cells).