TNF and Crohn disease: In further support of these proposed mechanisms, the transcript coding for tumor necrosis factor alpha (TNF-α; a pro-inflammatory cytokine of pathogenic importance in Crohn’s disease), as well as a number of additional tumor necrosis factor-related transcripts, has been shown to be present in excess in the inflamed intestinal mucosa as well as in their peripheral lymphocytes26,27 of GI symptomatic children with ASD.