To confirm the results of the initial study, B16-F10-LacZ-expressing tumor cells (2 × 105) were injected intravenously (IV) in immunocompetent mice and treated (through IV) with a control peptide, the PD1 peptide antagonists (Peptide Combo), or anti-PD1 mAb (Figure 5A). The gene discussed is PDCD1; the disease is neoplasm.