Comprehensive analysis reveals CLDN9 is a new biomarker in human cancers and immunotherapeutic target for glioblastoma multiforme

Abstract Background: Claudin-9 (CLDN9) plays a pivotal role in forming tight junctions and adhesion among epithelial cells. Despite its importance, comprehensive investigations into the role of CLDN9 in various cancers have been lacking. Methods: We conducted a thorough analysis of CLDN9 across multiple cancer types using omics data and assessed its expression in glioblastoma multiforme (GBM) tissues via immunohistochemistry. To explore the impact of CLDN9 on tumor growth, we employed a subcutaneous GBM animal model. Furthermore, we utilized transwell experiments