HIF1A and malignant colon neoplasm: In all, 39% (60 out of 155) and 53% (85 out of 159) of colon cancers were positive for nuclear HIF-1α and HIF-2α expression, respectively; 21% of cases (31 out of 147) expressed both HIF-1α and HIF-2α and 51% of cases (75 out of 147) expressed either HIF-1α or HIF-2α.