Characterization of the associated flora within colon cancer tumor tissues after application of Immune checkpoint blockade therapy revealed that Olsenella produces a metabolite called inosine, which enhances the effects of checkpoint blockade immunotherapy, particularly targeting cytotoxic T lymphocyte-associated antigen 4.[44] This result was similarly confirmed in bladder cancer, kidney cancer, and melanoma. The gene discussed is CTLA4; the disease is urinary bladder carcinoma.