Because our findings indicated that indoles induced Treg cells while suppressing Th17 cells in chickens, and Th17 is known to play a pathological role in coccidiosis (7, 44), we designed the in vivo experiment to determine the effect of DIM on the regulation of CD4+ T cells in E. tenella infection in chickens (Figure 4A). The gene discussed is CD4; the disease is coccidiosis.