MUC1 and cholangiocarcinoma: These anti-MUC1-CAR4 T cells showed anti-cancer activity against MUC1-expressing CCA cells by increased production of anti-tumor cytokines (TNF-α and IFN-γ), pro-apoptotic protein (granzyme B), and induction of CCA cell lysis both in 2D and 3D (spheroid) co-cultures.