HIF1α is often seen activated in larger hypoxic tumours, and thus we hypothesise that in tumours with decreased tumour burden often seen immediately after Enzalutamide treatment, there may not be an upregulation of HIF1α due to the absence of hypoxic environments and thus why we see HIF1α downregulation as reported by Cato. The gene discussed is HIF1A; the disease is neoplasm.