We next attempted to enhance the antitumor effect of CD47-deficient tumor cell vaccination by anti-PD-1 antibody in a therapeutic setting, in which tumor was established by subcutaneous injection of B16F10 cells (5 × 104 per mouse) 3 days before tumor cell vaccination, and some groups of mice were treated with 4 injections (i.p.)of anti-PD-1 antibody (clone RMP1-14; 250 μg per injection at days 7, 10, 13, and 16; Fig. 8a). Here, CD47 is linked to neoplasm.