PDCD1 and neoplasm: Given the treatment benefits were not seen in groups treated with single agents, as well as we only observed significant changes in the abundance of CD8+ tumor infiltrating T cells and antigen-specific CD8+ T cells in mice treated with CBDCA and anti-PD-1 antibodies (Figures 4A,B), we therefore focused on the tumor killing mechanism of CBDCA combined with anti-PD-1 antibodies.