The compact myelin sheath formed around nerve axons speeds up nerve conduction and also nurtures the axon. Destruction of this sheath in demyelinating diseases such as multiple sclerosis (MS) results in nerve conduction failure and neurodegeneration. Myelin basic protein (MBP) is the second most abundant protein of central nervous system (CNS) myelin (after the proteolipid protein), representing about 30 % of the total myelin protein and about 10 % of myelin by weight. It is also present in peripheral nervous system (PNS) myelin but as a lower percentage of the total protein. This book addresses the issue of Myelin and the way it binds to negatively-charged lipids on the cytosolic surfaces of the processes and is responsible for adhesion of these surfaces of myelin in the CNS, thus forming the major dense line observed by electron microscopy.