MAG(Myelin associated glycoprotein) is a type I membrane protein and member of the immunoglobulin superfamily. MAG plays a crucial role in the nervous system as a cell-surface adhesion protein that facilitates the connection between myelinating glial cells and neuronal axons. MAG is characterized by a sialic acid binding site and five immunoglobulin-like domains, classifying MAG within a specific subgroup of the immunoglobulin superfamily. This unique structure aids in the adhesion process and contributes to the inhibitory properties of myelin, which can impede axonal growth. Growth inhibition mediated by MAG can be counteracted when cerebellar neurons are pre-treated with neurotrophins such as brain-derived neurotrophic factor (BDNF) or glial cell line-derived neurotrophic factor (GDNF), suggesting these neurotrophins may enhance cellular signaling pathways, including the elevation of cyclic adenosine monophosphate (cAMP) and the activation of protein kinase A (PKA).