Scientists at Duke University School of Medicine have identified the molecular mechanism by which prostate cancer cells hide from the immune system, and developed a tool to reverse it, according to research published in Nature Biomedical Engineering on June 16, 2026. The findings provide one of the most specific molecular explanations yet for why prostate cancer is so consistently resistant to the checkpoint inhibitor immunotherapy drugs that have transformed treatment in melanoma, lung cancer, and bladder cancer.
The study was led by researchers from Duke and identified a protein called SPSB1 as a central driver of prostate cancer's immune evasion. When SPSB1 protein levels are elevated, it suppresses production of a molecular flag called MHC-I, which sits on the surface of cells and signals to immune T cells that something is wrong inside. Without sufficient MHC-I, immune cells cannot see the tumor, and immunotherapy drugs designed to remove brakes on T cell activity have nothing to target.
