Collagens are the most abundant proteins in mammals, comprising 28 members that contain at least one triple-helical domain. They play structural roles and contribute to the mechanical properties, organization, and shape of tissues. Collagens interact with cells via several receptor families and regulate cell proliferation, migration, and differentiation. The diversity of the collagen family is further increased by the existence of multiple α chains, molecular isoforms, and supramolecular structures. Collagens can form fibrils, beaded filaments, anchoring fibrils, and networks, each with distinct functions. Collagen biosynthesis involves posttranslational modifications and proteolytic cleavage, leading to the formation of bioactive fragments called matricryptins. Collagens are also involved in various diseases, including autoimmune disorders and genetic diseases caused by mutations in collagen genes. Understanding the functions of collagens and their interactions with other proteins is crucial for developing treatments for fibrotic diseases and other collagen-related disorders.Collagens are the most abundant proteins in mammals, comprising 28 members that contain at least one triple-helical domain. They play structural roles and contribute to the mechanical properties, organization, and shape of tissues. Collagens interact with cells via several receptor families and regulate cell proliferation, migration, and differentiation. The diversity of the collagen family is further increased by the existence of multiple α chains, molecular isoforms, and supramolecular structures. Collagens can form fibrils, beaded filaments, anchoring fibrils, and networks, each with distinct functions. Collagen biosynthesis involves posttranslational modifications and proteolytic cleavage, leading to the formation of bioactive fragments called matricryptins. Collagens are also involved in various diseases, including autoimmune disorders and genetic diseases caused by mutations in collagen genes. Understanding the functions of collagens and their interactions with other proteins is crucial for developing treatments for fibrotic diseases and other collagen-related disorders.