Laminins are basement membrane components thought to mediate the attachment, migration and organization of cells into tissues during embryonic development by interacting with other extracellular matrix components.

Laminin subunit alpha-3 is the alpha-3 chain of laminin 5, which is a complex glycoprotein composed of three subunits (alpha, beta, and gamma). Laminin 5 is thought to be involved in cell adhesion, signal transduction and differentiation of keratinocytes. Mutations in this gene have been identified as the cause of Herlitz type junctional epidermolysis bullosa. Alternatively spliced transcript variants encoding different isoforms have been identified.Alternatively spliced transcript variants encoding different isoforms have been identified for this gene.