In vivo studies in Balb/c mice showed that MVF-PD-1 (92-110) was emulsified with nor-MDP and Montanide ISA 720 VG and injected 3 times once every 3 weeks to immunize the mice produced high titers of anti-MVF-PD-1 (92-110) antibodies and was able to reduce the tumor growth of CT26 tumor cells engrafted 10 days after the last MVF-PD-1 (92-110) dose. The gene discussed is PDCD1; the disease is neoplasm.