PDCD1 and breast cancer: To model current PD-1-based immunotherapy in BC [4,35,36] and accelerate the implementation of human clinical trials with IT CPMV, we developed a monoclonal mouse antibody against canine PD-1 (acPD-1) and applied IT acPD-1 as a monotherapy or as a combined therapy with IT CPMV (IT CPMV/acPD-1) in six female CMC patients.