There is a biological rationale that IDH-mutated glioma shows lower cerebral blood volume due to lower levels of hypoxia-inducible-factor 1-alpha via the 2-hydroxyglutarate-mediated activation of EGLN prolyl 4-hydroxylases, and present a decrease in proangiogenic signaling that is reflected as lower cerebral blood volume in perfusion-weighted MRI in comparison with IDH wild-type glioma (62). The gene discussed is HIF1A; the disease is glioma.