On day 20 after subcutaneous inoculation, WT1-specific CTL frequency in CD8+ T cells in PB was inversely correlated with tumor volume (Fig. 2B; r2 = 0.6865, p < 0.0001) in mice treated with B. longum expressing WT1-derived CTL epitope including amino acid sequences 126–134 RMFPNAPYL in the B. longum 420 and B. longum 420/2626 combination groups. This evidence concerns the gene CD8A and neoplasm.