Although immune checkpoint monotherapy has failed to show significant benefits in prostate-cancer-specific clinical trials [28,32,33], our studies suggest that vaccination against AR-V7 and potentially other AR variants can expand AR-specific T cells, which in combination with PD-1 immune checkpoint inhibition, allow for significant anti-tumor responses in AR-V7+ immunosuppressive tumor microenvironments. The gene discussed is AR; the disease is neoplasm.