AR and small cell carcinoma: Using AR expression to denote luminal-like adenocarcinoma and neuroendocrine (NE) expression to denote stem-like small cell carcinoma, prostate cancer differentiation (from NE+ stem-like to AR+ luminal-like) and de-differentiation (from AR+ luminal-like to NE+ stem-like) can describe a proposed lineage relationship among the different cancer cell types (Fig. 7).