During tumor invasion and metastasis, cancer cells interact with host tissues. Penetration of the extracellular matrix by cancer cells is mediated in part by interaction of cell surface receptors with laminin, the major glycoprotein component of the basement membrane. A variety of cell surface laminin binding proteins have been identified, including members of both the integrin and non-integrin families. The 67 kDa laminin receptor is a non-integrin protein with a high affinity for laminin. Immunohistochemical, immunoblot, RNA blot and in situ hybridization studies have demonstrated that levels of 67 kDa laminin receptor protein and/or mRNA are increased in a variety of human adenocarcinomas. In contrast, cancers of squamous cell origin may not demonstrate the same pattern of laminin receptor expression.