Our results show that tumor epithelial cells in PCa bone metastases possibly synthesize cholesterol de novo via HMG-CoA reductase, but also that other cell types in the bone metastases micro-environment express this enzyme possibly allowing them to provide cholesterol that could be taken up by tumor epithelial cells through the LDL and SRB-1 receptors (Figure 3f). The gene discussed is HMGCR; the disease is posterior cortical atrophy.