The present study aimed to investigate the differences between a 3-year-old girl’s high-grade SF8628 cell line xenograft and a 13-year-old boy‘s high-grade PBT24 cell line [40] xenograft using the CAM model; to examine the tumor response to treatment with TMZ’s effect on PCNA and EZH2 histological expression in cells of the tumor in the CAM; and to investigate the impact of TMZ on the NKCC1, KCC2, E- and N-cadherin gene expression in the studied phGBM cells. This evidence concerns the gene EZH2 and neoplasm.