IL4 and irritable bowel syndrome: In particular, 136 (UC) and 246 (CD) transcripts known to be involved in positive regulation of cytokine production were overexpressed in inflamed mucosa, including pathways for the production of IL-1, IL-2, IL-4, IL-6, IL-8/CXCL8, IL-10, IFNγ, and TNF, which were also upregulated in other IBD studies29,30.