EGFR and posterior cortical atrophy: PCa cells can maintain AR signaling, proliferation, and survival in an androgen-deprived milieu through activation of nonsteroidal growth factor receptors, including vascular endothelial growth factor receptor (VEGFR), insulin-like growth factor receptor (IGFR), keratinocyte growth factor receptor (KGFR), epidermal growth factor receptor (EGFR), transforming growth factor receptor β (TGF β-R), and interleukine-6 receptor (IL6-R).