The elevated levels of γH2AX observed in the nuclei of TMZ-treated glioma cells suggest that TMZ-induced DNA alkylation in these cells is not successfully repaired by pathways like the O6-methylguanine-DNA methyltransferase pathway and mismatch repair, but instead progresses to the final step of DNA damage: DSBs. The gene discussed is MGMT; the disease is central nervous system cancer.