CD274 and neoplasm: employed several groups of mice (i.e., specific pathogen‐free (SPF) mice with gut microbiome, germ‐free (GF) mice without a gut microbiome, the GF mice reconstructed by healthy human or mouse microbiota (HMB/MMB), SPF mice were depleted of gut commensals by four oral antibiotics (ABX) or reconstructed by HMB (ABX/HMB)) to implant with tumor and treated with anti‐PD‐1/PD‐L1, and found that the anti‐tumor effect was disappeared in the mice without microbiota, which was regained by HMB.