AR and prostate adenocarcinoma: Neuroendocrine prostate cancer (NEPC) comprises an aggressive form of the disease that can arise de novo but more often forms as a consequence of the selective pressure of androgen deprivation; NEPC tumours are notable for their diminished AR signalling, increased expression of neuroendocrine lineage markers including chromogranin-A, neuron-specific enolase and synaptophysin, and their pure/mixed small cell histology.56 Genetic alterations, such as the loss of RB1 and TP53 and amplification of MYCN and AURKA, are more prevalent in NEPC compared with prostate adenocarcinoma.