On the other hand, resistance can also develop due to mechanisms intrinsic to the biology of mCRPC like continued AR signaling which stimulates PCa growth and inhibits apoptosis (Seruga et al. 2011) or due to the activation of compensatory oncogenic pathways (such as PI3K/AKT or MAPK/ERK Zhu & Kyprianou 2008) which are themselves associated with proliferation and survival. The gene discussed is AR; the disease is posterior cortical atrophy.