H2AX and glioblastoma: Additionally, DBTRG-05MG GBM cells treated with compound 3 (at doses of both 5 and 10 μM), a high dose of compound 4 (at 5 and 10 μM), and TMZ (at doses of 100 and 500 μM) exhibited marked H2AX phosphorylation (γH2AX; Supplementary Figure S3).