The complement system helps or "complements" the ability of antibodies and phagocytic cells to clear pathogens from an organism.
Interferons (IFNs) are proteins made and released by host cells in response to the presence of pathogens.
Natural killer cells (or NK cells) are a type of cytotoxic lymphocyte critical to the innate immune system.
Toll-like receptors (TLRs) are a class of proteins that play a key role in the innate immune system as well as the digestive system.
Iron binding proteins of the innate immune system include lactoferrin and transferrins.
Antimicrobial peptides are an evolutionarily conserved component of the innate immune response and are found among all classes of life.
In autoimmune heart diseases, the body's immune defense system mistakes its own cardiac antigens as foreign, and attacks them.