Contactin
Contactins are a subgroup of molecules belonging to the immunoglobulin superfamily that are expressed exclusively in the nervous system. These proteins are attached to the neuronal membrane by a GPI-anchor. The subgroup consists of six members now referred to as contactin 1-6, but historically they had different names as shown in the table below:
| New name | Old name |
| Contactin 1 | Contactin |
| Contactin 2 | TAG-1 |
| Contactin 3 | BIG-1 |
| Contactin 4 | BIG-2 |
| Contactin 5 | NB-2 |
| Contactin 6 | NB-3 |
