IL-17-Active Subset Found in 5% of Clear Cell Ovarian Cancers Shows Preclinical Immunotherapy Response

The Kindai University-led study combined retrospective genomic profiling of 180 patient samples with syngeneic mouse models recapitulating human clear cell histology. IL-17-high tumors displayed NF-κB activation, chemokine secretion, and CD8+ T-cell recruitment independent of conventional PD-L1 or tumor mutational burden markers. Anti-PD-L1 treatment extended survival only when IL-17 signaling was intact, converting immunologically cold lesions into inflamed states. These mechanistic data extend beyond the MedicalXpress summary by quantifying the responsive fraction and ruling out overlap with existing biomarkers. Observational human data plus interventional mouse experiments cannot yet establish clinical utility; a prospective biomarker-stratified trial is required to test whether IL-17 expression predicts objective response rates above 30% in checkpoint-inhibitor-treated patients.