Table 1.

Immunohistochemical analyses of expression of glial acidic fibrillary protein (GFAP) and the human poliovirus receptor (CD155) in human malignant gliomas^*

No. of tumors tested	Histological grade	No. of tumors positive for
		GFAP	CD155
6	I/II	6	6
	Low-grade astrocytoma
6	III	6	5
	Anaplastic astrocytoma
	Anaplastic oligodendroglioma
13	IV	13	8
	Glioblastoma multiforme

^*Glioma tissue obtained through craniotomy was processed and immunohistochemically analyzed as described (20). Biochemical properties of CD155 are described in ref. 22.