Pre-treatment with anti-CD40 mAb and vaccination with SIY−Kb-Ig as well as with TRP2−Kb/gp100−Db-Ig induces an endogenous SIY or tumour-antigen (TRP2/gp100) specific T cell response that significantly inhibited tumour growth in a B16-SIY melanoma mouse model (Fig. 6). The gene discussed is CD40; the disease is neoplasm.