The pore forming components of complement (C8α and C9), Perforin-1, and Perforin-2 all contain membrane attack complex perforin (MACPF) domains and amino-terminal signal peptides (SPs). MACPF domains are also present in other components of complement (C6, C7, and C8β). The presence of a MACPF domain within Perforin-2 suggest that it is also a mediator of innate immunity. Unlike C6-C9 and Perforin-1, Perforin-2 is predicted to be an integral membrane protein because it alone contains a membrane spanning alpha helix (TM) followed by a short cytosolic tail. An additional distinguishing feature of Perforin-2 is the P2 domain which is of unknown function but conserved amongst Perforin-2 orthologs. Domain architecture was retrieved from UniProt entries P07357, P02748, P14222, and Q2M385. TSP1, thrombospondin type-1 repeat; LDL, low-density lipoprotein receptor class A repeat; EGF, epidermal growth factor-like domain; C2, calcium-dependent phospholipid binding domain.