Consistent with the emergence of Tr1 cells from Th1 subsets, the majority of Tr1 cells where Th1-like (CXCR3+/CCR6-/CXCR5-/FoxP3-) at day 0 during malaria (median 65.4%, IQR 62.5-73.8%, Supplementary Fig. 15B). The gene discussed is CXCR5; the disease is malaria.