Since the approval of Sipuleucel-T in 2010, Immunotherapy has become an intriguing option also for PCa patients; conversely, PCa represents a very interesting histology for the development of immunotherapeutic agents, due to its intrinsic immune-stimulating characteristics; unfortunately, in trials conducted with anti-CTLA4, in particular Ipilimumab, a significant impact on outcomes has not been observed. This evidence concerns the gene CTLA4 and posterior cortical atrophy.