Autologous T cells are engineered ex vivo to express a chimeric antigen receptor that recognizes Cadherin 17 (CDH17). Upon binding CDH17 on tumor cells, the CAR triggers T‑cell activation, cytokine release, proliferation, and perforin/granzyme-mediated cytotoxicity independent of the native TCR, leading to targeted killing of CDH17-positive gastrointestinal tumors; lymphodepletion is used to enhance expansion and persistence.