Abstract: Oligodendrocytes (OLs) are highly specialized cells of the central nervous system (CNS). Their primary and most investigated role is to form myelin, a multilamellar fatty membrane that enwraps axons ensuring their insulation and the saltatory conduction of nerve impulses. The formation of myelin is a complex process during which the OL precursor cells (OPCs, also known as NG2-glia) become mature OLs through a highly regulated program of differentiation. In addition, OPCs persist in the adult grey and white matter parenchyma, representing approximately 6% of the total number of CNS cells. Beyond their role in myelin generation and turn-over, it is now clear that OPCs have the capability to control tissue homeostasis and to sense and react to inflammation which characterizes many neurological diseases.