TNF and inflammatory bowel disease: This study investigated the effect of three cytokines IL-1β, TNF-α, and IFN-γ on PDZK1 gene expression in Caco-2BBE cells, since these cytokines were known to be released in the mucosa of IBD patients (Reinecker et al., 1993; Dionne et al., 1997; Raddatz et al., 2005; Matsuda et al., 2009; Yeruva et al., 2010, 2015).