Moreover, all four D4 CAR T cells dramatically downregulated β-catenin expression in T3M4 cells, with the exception of IgG4H(mut)-CD28TM CAR likely due to its impaired binding ability to GPC1 (Fig. 8d), indicating that GPC1 CAR T cells may downregulate the Wnt/β-catenin signaling in target pancreatic tumor cells. Here, GPC1 is linked to pancreatic neoplasm.