The stromal component of BPH samples demonstrated a high degree of ITH in antigen processing and presentation, naive CD8+ T cell signaling, IL-12-mediated signaling, interactions between a lymphoid and a nonlymphoid cell, MHC class I complex expression, and natural killer-cell–mediated cytotoxicity, suggesting the combat between carcinogenesis and immunity. The gene discussed is CD8A; the disease is benign prostatic hyperplasia.