CD4 and inflammatory bowel disease: Although CD4+ T cell responses are conventionally thought to be associated with pathogenesis of IBD, transcriptional profiling of circulating T cells isolated from patients with IBD has previously shown a CD8+ T cell signature associated with more severe disease.90 Further, adoptive transfer of naïve CD8+ T cells to immunodeficient mice results in colitis in vivo.91 It is clear that innate immune pathways affect the nature of CD8+ T cell response.