Preclinical studies in mice have highlighted the critical role of gut microbiota in mediating tumor responses to chemotherapeutic agents48, 49, 50 and immunotherapies targeting PD‐L1 or CTLA‐4.51, 52, 53, 54 The diverse types and variable distribution of gut microbes affect the degree of T‐cell infiltration into tumors, which is closely related to natural antitumor responses. This evidence concerns the gene CTLA4 and neoplasm.