When inside a host, the parasite's main opposition is to affect the immune response of said host. The parasites in the phylum Acanthocephala are characterized by their thorny proboscis which they use to attach to the intestinal tissue of aquatic mammals, fish and birds. Acanthocephala in the genus Corynosoma are found to inhabit harbor seals (Phoca vitulina) in the Northwestern United States (OR, WA). It has been shown that infection by Acanthocephala has led to lower levels of immune response. Parasites of the phylum Platyhelminthes have shown expression of Cathepsin L3 (CL3) which is responsible for the parasites' induction of immunosuppression of their host. It is hypothesized that the genome of the CL3 cysteine protease in Platyhelminths has been conserved evolutionarily and is present in Corynosoma. This leads to the belief that there is a close phylogenetic relationship between Corynosoma and Platyhelminths and CL3 expression could potentially explain immunosuppression in Phoca vitulina by Corynosoma. PCR performed on Corynosoma using primers from Platyhelminthes, specifically Fasciola Hepatica and Eudiplozoon nipponicumn were used to identify the presence of the CL3 genome. Bands during electrophoresis found from the genome of Fasciola Hepatica, indicates that this genome is conserved in the genus Cornysoma. PCR purification to identify the exact genome will allow for confirmation of CL3 expression as well as indication of phylogeny amongst phylums of immunosuppressive parasites with CL3 expression.