MAPK9 and infection: Since NF-κB is considered a central regulator/activator of the proinflammatory gene program we decided to examine the effect that non-flagellin producing mutant strains of Salmonella had on activation of the MAPK, SAPK and IKK signaling pathways compared to infection of intestinal epithelial cells with wild-type Salmonella or by exposure of the intestinal epithelial cells to purified flagellin.