MKI67 and neoplasm: In addition, weobserved many GFAP+ reactive astrocytes scattered throughout the tumor.However, none of these cells are YFP+, ki67+ or Phospho-histone H3(PHH3)+ (Figure 3H, K,N and data not shown), suggesting that the GFAP+ cells are notderived from virally infected cells and do not represent a neoplasticpopulation.