Although TLR7 deficiency can significantly increase the percentage of PD-L1 or PD-L2-expressed MDSCs in mouse lung after infection (Fig 4B), which indicated that TLR7 deficiency promoted the immunosuppressive function of S. japonicum infection-induced MDSCs by up-regulating the expression of PD-L1 or PD-L2 in mouse lung after infection. Here, TLR7 is linked to infection.