Abstract Despite breakthroughs in immune checkpoint inhibitors (ICIs) across various malignancies, prostate cancer (PCa), particularly metastatic castration-resistant prostate cancer (mCRPC), has shown limited responses to ICIs. This pervasive primary resistance is fundamentally driven by the canonically “immune-cold” and highly immunosuppressive tumor microenvironment (TME) of PCa. Propelled by recent advancements in single-cell RNA sequencing and spatial transcriptomics, this review...