Collectins (collagen-containing C-type lectins) are a part of the innate immune system. They form a family of collagenous Ca²⁺-dependent defense lectins, which are found in animals. Collectins are soluble pattern recognition receptors (PRRs). Their function is to bind to oligosaccharide structure or lipids which are on the surface of microorganisms. Like other PRRs they bind pathogen-associated molecular patterns (PAMPs) and also danger-associated molecular patterns (DAMPs) of oligosaccharide origin. Binding of collectins to microorganisms may trigger elimination of microorganisms by aggregation, complement activation, opsonization, activation of phagocytosis or inhibition of microbial growth. Other functions of collectins are modulation of inflammatory, allergic responses, adaptive immune system and clearance of apoptotic cells.