Overexpression of NF-κB subunits (p50 and p65) and NF-κB target genes [matrix metalloproteinase (MMP)-3, MMP-9, IL-1β, IL-6, and IL-8] in esophageal epithelium at 4 wk after duodenal or mixed reflux. A: immunohistochemical staining for NF-κB p50, NF-κB p65, MMP-3, and MMP-9. B: ELISA of IL-1β, IL-6, and IL-8. Values are means ± SE. *P < 0.05, **P < 0.01 vs. control.