Laminin 332 (iMatrix-332) is a large multidomain molecule involved in cell adhesion and matrix assembly. Laminin 332 supports cells in the epithelial basement membranes, lining the surfaces of the body such as the skin, hair follicles, oral cavity, gastrointestinal and urinary tracts, lungs, and different glands. The association of cells with laminin 332 occurs through α3β1 integrin in focal adhesions and α6β4 in stable anchoring contacts, which contain an assembly of hemidesmosome proteins.

Proteolytic processing of the γ2 and α3 chains of laminin 332 has been linked to cell migration and invasion. Members of the astacin family process the γ2chain, and various enzymes, including astacin enzymes, matrix metalloproteinase 2 (MMP2), MT1-MMP and plasmin process the α3 chain.

It is an important component of the "skin basement membrane" that exists between the epithelium and dermis of the skin, and is also expressed in human retinal pigment epithelium (RPE) and hair follicle cells.