These patterns not only highlight EXT1 and EXT2 as predictive biomarkers of drug responses but also suggest that targeting replication stress checkpoints (ATR/CHK1 inhibitors) or actin-myosin pathways (ROCK/FAK inhibitors) may selectively sensitize EXT1- or EXT2-driven gliomas, respectively 85. This evidence concerns the gene EXT2 and central nervous system cancer.