SLC9A2 and irritable bowel syndrome: Given the multitude of proinflammatory cytokines secreted under the pathological condition of IBD, both TNF-α (tumor necrosis factor α) and IFNγ (interferon γ) could suppress NHE2 expression and activity in the intestinal epithelial cells through NF-κB activation (Rocha et al., 2001; Amin et al., 2011).