Edward, Ng, and colleagues compared their Tr1 signature from people infected with malaria to previously published signatures of Tr1 cells from people infected with dengue virus (6) and Tr1 cells generated — for the purpose of treating GvHD — by ex vivo activation of peripheral blood-derived naive CD4+ T cells in the presence of tolerogenic dendritic cells (DC-10) and IL-10 (15). The gene discussed is IL10; the disease is malaria.