Excised tumors consistently corroborated the significant tumor‐suppressing activity of B7 (Figure 6D,E, both P < 0.05 vs vehicle), which was attenuated by CD155 overexpression (Figure 6D,E, P = 0.06 vs vehicle + B7 10 mg kg−1, P < 0.05 vs vehicle + B7 20 mg kg−1). This evidence concerns the gene CD80 and neoplasm.