A potential perforin exist in Schmidtea that is related to other known perforins. We identified a perforin-like protein in the Schmidtea cDNA library. Using corresponding EST sequence and further EST sequences from the public database (DN313739, EG343971, DN299412, DN307006) we constructed the potential full-length protein. The alignment with perforin sequences from Haliotis corrugata (AAR82935), Homo sapiens (AAI12231), Danio rerio (XP_688214), and the sponge Suberites domuncula (CAI68018) reveal that perforins are conserved in evolution. Red color indicates 90% consensus and blue color 40% consensus.