RUNX3 and neoplasm: Hypoxia, often found in solid tumors larger than 1 mm3, as well as in pathophysiolocial premalignant conditions [15], downregulates RUNX3 by promoter histone deacetylation and methylation in gastric cancer cells [16], suggesting that histone modification plays a role in RUNX3 inactivation in early tumorigenesis and tumor growth.