APOE and glioblastoma: Instead, cholesterol in the brain is synthesized in astrocytes and delivered to neurons through the apolipoprotein E (APOE).30 Notably, a recent study showed that the demand for cholesterol in glioblastoma cells was mainly exogenous rather than endogenous,31 which has also been suspected to be the underlying cause of developing drug resistance in glioblastoma.31 This study also highlights the importance of cholesterol sources in glioblastoma progression.