The dietary indole derivative I3C was found to elevate the CD4+ RORγt+ Foxp3− Th17 cell numbers in the intraepithelial layer, lamina propria, and Peyer’s patches of the small intestine, improving the progression of type 1 diabetes (T1D) in non-obese diabetic (NOD) mice (243). The gene discussed is FOXP3; the disease is type 1 diabetes mellitus.