CD49a is a 200kD type I transmembrane glycoprotein, also known as a1 integrin, VLA-1 a chain, or Integrin a1. It associates with CD29 (B1 integrin) to form VLA-1 complex, a collagen IV and alminin-1 receptor and that is expressed on activated T cells, monocytes, NK cells, smooth muscle cells, neuronal cells, fibroblasts, and mesenchymal cells.CD49a is an adhesion molecule and is involved in the regulation of leukocyte migration and T cell proliferation and cytokine production.