Temozolomide, an oral DNA alkylating agent, represents a common first-line therapeutic option for recurrent GBM, especially with a positive methylation status of the MGMT promoter (Minniti et al., 2021; Balañá et al., 2011; Rodríguez-Camacho et al., 2022). The gene discussed is MGMT; the disease is glioblastoma.