We found that 14% of patients with PCa displayed higher antibody levels against HERV-K env-su109–126 compared to HCs, BPH and the borderline cohorts, while no differences were found in the humoral response against the peptides derived from the envelope protein of HERV-W (HERV-W en-su93–108 and HERV-W env-su248–262). This evidence concerns the gene ERVW-1 and benign prostatic hyperplasia.