Here, we found IFN-I promoted PD-1, but not LAG3 or CTLA4 expression in both CD4+ and CD8+ T cells during toxoplasmosis, which was partly consistent with a recent report that IFN-I induces PD-1/TIM-3/LAG-3 while inhibiting TIGIT expression in human T cells (82), but the underlying mechanism needs to be further explored. Here, CD4 is linked to toxoplasmosis.