RAB27A and Familial prostate cancer: More importantly, the administration of exogenous exosomes derived from wild-type (Newton et al., 2016) prostate cancer cells leads to immunosuppression in the draining lymph node, as evidenced by a reduced number and effector function, and increased exhaustion of CD8+ T cells of mice injected with Rab27a-deleted prostate cancer cells (Poggio et al., 2019).