Laminin-121 is one of the α1 chain containing laminins. The α1 chain is detected at the 2-cell stage of the pre-implantation mouse embryo and is subsequently expressed mainly in many epithelial tissues during organogenesis. Laminin-121 showed the highest affinity to α6β1 and α7β1 integrins and furthermore, laminin-121 most effectively supported neurite outgrowth.