The use of a Programmed Death (PD-1) antagonist and a tumour antigen for treating a mammalian subject having a tumour. The antagonist can be an anti-PD1 antibody, an anti-Programmed Death Ligand 1 (PD-L1) or an anti-PD-L2 antibody； a siRNA or antisense RNA directed to PD-1, PD-L1 or PD-L2； or a dominant negative PD-1, PD-L1 or PD-L2 protein. The tumour antigen can be PRAME, WT1, surviving, cycin D, cyclin E, proteinase 3 and its peptide PR1, neutrophil elastase, cathepsin G, MAGE, MART tyrosinase, GP100, MY-Eso-1, Herceptin, carcino-embryonic antigen (CEA) or prostate specific antigen (PSA).
