Luciferase reporter assay showed that hypoxia induced NF-κB activation in SNU-668Vector cells after 2 h of hypoxia (P=0.009 vs normoxic control), and that basal NF-κB activity was essential for hypoxia-induced NF-κB activation in gastric cancer cells (Figure 5A). Here, NFKB1 is linked to gastric cancer.