Prolgolimab is a reference antibody targeting the PD-1 (CD279) receptor, primarily used in immuno-oncology research and therapeutic development. It functions by blocking the interaction between PD-1 and its ligands PD-L1 and PD-L2, thereby restoring T-cell activity and enhancing anti-tumor immune responses. This antibody serves as a critical tool for benchmarking biosimilar development and evaluating the efficacy of novel checkpoint inhibitors. It is widely used in preclinical studies to assess tumor immunotherapy mechanisms, including immune cell activation, cytokine production, and tumor cell killing in various cancer models. Additionally, prolgolimab supports pharmacodynamic and pharmacokinetic studies due to its well-characterized binding properties and high specificity. Its role as a reference standard ensures consistency and accuracy in comparative studies across different drug candidates targeting the PD-1 pathway.