To the best of our knowledge, our study will be the first to demonstrate the tumor IFN signaling as a novel PDA-intrinsic mechanism that contributes to PDA resistance to tumor MUC1-targeted CAR T cell therapy, and such mechanism may be universal and essential that most or all PDA tumors use in their resistance to tumor antigen-targeted T cell therapy beyond tMUC1-CAR T cells. Here, MUC1 is linked to Patent ductus arteriosus.