AR and neoplasm: A recent classification of neuroendocrine prostatic tumors26 showed variants of neuroendocrine prostate cancer, including a mixed form between NEPC and conventional adenocarcinoma, usually characterized by AR independence, However, mixed tumors have been also observed with both AR positive and AR negative cells and, on occasion, with dual expression of both neuroendocrine markers and AR in the same tumor cells due to inter- and intra-patient clinical and pathologic heterogeneity.