To analyze transduction specificity, histological sections of invasive tumor areas were stained for rat specific markers NeuN (for neurons) and nestin (for astrocytes and progenitor cells). LCMV-GP pseudotyped lentiviral vectors exclusively transduced tumor cells in all invasive areas ( Figure 4A ), while normal brain cells were not transduced ( Figure 4B,C) . Also VSV-G pseudotyped vectors showed specific transduction of tumor cells in some invasive areas ( Figure 4D,E) , however, they also transduced a few host brain cells at other sites ( Figure 4G,H) .