IL6 and inflammatory bowel disease: Pro-inflammatory cytokines TNF-α and IFN-γ were added in concentrations of 25 or 100 ngml to the top (Caco2-cultured) or bottom (HUVEC-cultured) channel, and the responding secretion of IBD-relevant cytokine and chemokines IL-6, IL-8, and CXCL-10 was measured using an ELISA assay.