In summary, the strong activity of OlPC on C. parvum parasites in vitro was thoroughly supported by the outcome of the animals in our in vivo study as OlPC rescues C57BL/6 IFNγR-KO mice from a lethal infection of C. parvum. Data obtained by qPCR from the in vivo study was not only cross-validated by flow cytometry and light microscopy, but was also confirmed visually by histological sections from mice ileums. This evidence concerns the gene IFNGR1 and infection.