TIGIT and posterior cortical atrophy: In our study, the proportion of Tregs in high-RS patients was higher, the expression levels of the immune checkpoints CTLA-4, PD-1, LAG-3, TIM-3 and TIGIT were higher, and the prognosis was poor, suggesting that the immunosuppressive environment and the high expression of immune checkpoints may be the reasons for the poor prognosis of PCa.