An integrin found on Fibroblasts, Platelets, endothelial and Epithelial Cells, and Lymphocytes where it functions as a receptor for Collagen and Laminin. Although originally referred to as the Collagen Receptor, it is one of several receptors for Collagen. Ligand binding to integrin alpha2beta1 triggers a cascade of intracellular signaling, including activation of p38 MAP Kinase.