Oligodendrocytes stained by Olig1 represent myelinating and oligodendrocyte progenitors (Arnett et al., 2004), and immunolabeling with other oligodendrocyte markers such as 2’,3’-cyclic nucleotide 3’-phosphodiesterase (CNP), GalC or myelin basic protein (MBP) is necessary to investigate possible myelin damage or whether more mature forms of these glia cells are altered in schizophrenia. The gene discussed is CNP; the disease is schizophrenia.