PRF1 and colorectal carcinoma: Further analysis revealed that, compared with those in the CRC control group, treatment with F. rodentium and its metabolites significantly promoted TNF-α, IFN-γ, granzyme-B, and perforin production in CD8+ T cells from the spleen, MLNs, and tumors (Fig. 3A through C), suggesting that F. rodentium and its metabolites may inhibit CRC by promoting CD8+ T-cell responses.