Cell migration is central to many physiological and pathological events, such as embryonic development, wound healing, immune response, and tumor metastasis. This is a highly integrated, multi-step process that plays an important role in the progression of various diseases including cancer, atherosclerosis and arthritis.
The induced signals are received by transmembrane proteins, such as CD antigens, expressed on the surface of migrating cells. Migrating cells are thought to read and decipher gradients of the signals, leading to polarized cell protrusions which like as blebbing or lamellipodia and directional migration towards the highest levels of signals. This is accomplished by the localized polarization of migrating cells and cytoskeletal rearrangements, brought about by downstream signalling effectors and small GTPases. For example, the GPCR chemokine receptor type 4 also known as CD184, mediates attraction of many cell types, including zebrafish and mouse primordial germ cells towards the chemoattractant CXCL12. Certainly, there are other CD antigens can regulate the cell migration, such as CD9, CD11a and CD18.