Hypoxia inducible factor-1a (HIF-1α) controls the overexpression of the enzyme Cyp46a1, which generates the oxysterol 24-hydroxycholesterol in a pancreatic neuroendocrine tumor (pNET) model commonly used to study neoangiogenesis. The activation of the HIF-1α-24S-HC axis ultimately leads to the induction of the angiogenic switch through the positioning of proangiogenic neutrophils in proximity to Cyp46a1 islets. 24-hydroxycholesterol levels are increased at 2-4 months in the untreated 5XFAD mouse brain and then became similar to those in the B6SJL mouse brain.