Myelin basic protein (MBP) and proteolipid protein (PLP) were highly expressed in all oligodendrogliomas and minimally expressed in glioblastoma multiforme. MBP was highly expressed in mixed oligoastrocytomas, whereas PLP expression was minimal. The association between tumor classification and expression of the MBP and PLP genes was statistically significant. Expression of these genes may serve as a useful molecular marker for some subtypes of human gliomas ¹⁾.