PDCD1 and neoplasm: (21) conducted a study on the treatment of newly diagnosed DLBCL with pembrolizumab in combination with R-CHOP, taking into account the relatively intact immune function of first-line treatment patients, the tumor microenvironment where tumor cells and T cells coexist, and the potential synergistic mechanism of anti-PD-1 mAb in combination with R-CHOP.