Work on prostate-specific membrane antigen (PSMA) mapped naturally processed, MHC-II–restricted helper epitopes, notably PSMA459 (NYTLRVDCTPLMYSL), which activated human CD4+ T cells across multiple HLA-DR alleles and primed responses in HLA-DR4 transgenic mice, evidence that class II ligands can be leveraged to sustain CTL responses and memory in PCa (154). Here, CD4 is linked to posterior cortical atrophy.