The TMP1 peptide derived from enterococci (a type of intestinal bacteria) shares a strong homology with a peptide of proteasome subunit beta type-4 (PSMB4, a tumor antigen), and this homology arouses the bacteria-dependent antitumor activity of CD8+ T cells in an HLA-restricted manner (Fig. 8B). This evidence concerns the gene PSMB4 and neoplasm.