Group 3 ILCs (ILC3), secreting IL-17 and IL-22 and expressing the transcription factors RORγt and AHR regulate intestinal immunity [6,7,29], and preliminary analysis of altered mRNA expression characteristic of such cells (S1 and S2 Figs) in tissue from acute/chronic colitis mice are consistent with their also playing a role in this model. The gene discussed is AHR; the disease is Chronic colitis.