CD274 and neoplasm: By conducting a comparative examination of the gut microbiome's composition and relative abundance (focusing on taxa with relative abundance exceeding 1%), both pretreatment and posttreatment periods were evaluated; we observed significant changes in the gut microbiota following PD-L1 inhibitor immunotherapy (pos-pdl1t [after tumor implantation and before PD-L1 inhibitor treatment] vs. tpos-pdl1t) and USMC combined with PD-L1 inhibitor immunotherapy (pos-um-pdl1t [after tumor implantation and before USMC+PD-L1 inhibitor treatment] vs. tpos-um-pdl1t).