To find out which cell subset played a key role in inducing antitumor immunity, we compared 3 × 107 T cells (TCRβ+CD19−), 5 × 107 B cells (TCRβ−CD19+) as well as 1 × 106 DCs (TCRβ−CD19−CD11c+Ia+), respectively, from DBA/2 mice with those from B6 mice, in their antitumor efficacy as tumor vaccines. The gene discussed is CD19; the disease is neoplasm.