Laminins are extracellular matrix proteins which consists of α, β and γ chains with molecular masses of 140–400 kDa. Chain association occurs through a large triple α-helical coiled-coil domain towards the C-terminus of each chain. Eight genetically distinct laminin chains (α1, α2, α3, β1, β2, β3, γ1, γ2) and seven different assembly forms (laminins-1 to -7) are known so far. The most extensively characterized laminin-1 (α1β1γ1) shows calcium-dependent self assembly and heterotypic binding to perlecan, nidogen, fibulin-1 and other matrix components. This binding indicates a crucial role in the supramolecular organization of basement membranes. Laminins also possess binding sites for at least six different integrin receptors and are thus involved in many cell-matrix interactions. Such interactions have been shown to be important during embryonic development and for tissue homeostasis and remodelling.