The extracellular space surrounding each cell is called the extracellular matrix (ECM). Among different types of ECM proteins, those that "integrate" (or tether) cells to the ECM are called integrins.
The ECM of different cells is "adhered" to one another by a class of proteins called cadherins. Cadherins come in two forms: pro-cell adhesion and anti-cell adhesion.
The best studied pro-adhesion cadherin is called E-cadherin (or E-cad). The best studied anti-adhesion cadherin is called N-cadherin (or N-cad). Not surprisingly, in cancer cells, E-cad activity is substantially reduced, whereas N-cad activity is significantly elevated. These parallel events enable cancer cells to be highly mobile and capable of migrating to neighboring tissues or distal organs, a phenomenon called metastasis.
