B7-H4, a sibling to PD-L1 in B7 family, has been reported to be a novel immune checkpoint that is prevalent among non-inflamed tumors. Herein, we attempt to explore the potential of B7-H4 in survival prediction and therapeutic guidance in muscle-invasive bladder cancer (MIBC) patients.This study included 391 patients from The Cancer Genome Atlas (TCGA) database and 122 patients from Zhongshan (ZS) Hospital. The evaluation of response to PD-L1 inhibitors was based on 270 patients in IMvigor210 cohort. Kaplan-Meier survival and multivariate analyses were performed to assess clinical outcomes in three cohorts. The correlation of B7-H4 expression with immune contexture and genomic alterations was analyzed based on immunohistochemistry, Microenvironment Cell Populations-counter (MCP-counter) tool, and whole-exome sequencing.MIBC patients with the high level of B7-H4 expression (B7-H4Despite adverse clinical outcomes, B7-H4
