CDKN1A and glioblastoma: Studies have shown that MGMT silencing is linked to mutations in other tumor-related genes, such as p53, k-ras, and CDKN1A/2A, which are markers of poor prognosis.8 Although the relationship between methylation of genes in carcinogenesis is not entirely clear, these findings suggest that MGMT promoter methylation likely has an impact on GBM tumor biology beyond treatment resistance.