Detailed analysis of infection with a modified strain of EHV-1 (strain L11ΔgIΔgE, deletion of gI and gE glycoproteins, and embedded LacZ cassette) on five glioblastoma multiforme cell lines (A172, Hs 683, LN-18, SNB19, U251) was conducted to assess the oncolytic potential of the virus. This evidence concerns the gene GNAI1 and infection.