In parasitic infections, PD-1/PD-L1 or PD-1/PD-L2 signaling has been reported to be involved in the immune responses to protozoa, nematode, trematode, and cestode infections [32]; however, the effect of a C. hepatica infection on the regulation of the PD-1/PD-L1 or PD-L2 signaling pattern has not been previously reported. This evidence concerns the gene PDCD1LG2 and Cestode Infections.