Considering that PD-L2 is involved in both the regulation of T cell activation and tolerance [16], together with the fact that in our study F. hepatica infected PD-L2 KO mice showed a strong inflammatory liver damage, we hypothesized that PD-L2 expression is important for maintaining a survivable Th1 and Th2 cell balance during this infection. The gene discussed is PDCD1LG2; the disease is infection.