Since there had been reports that DIRAS-3, a third member of the distinct subfamily of small Ras GTPases, enhanced sensitivity of ovarian cancer cells to chemotherapeutic agents [20], we were especially interested if DIRAS-1 or DIRAS-2 overexpression can sensitize glioblastoma cells to chemotherapeutic agents such as temozolomide or nitrosourea (e.g., lomustine = chlorethyl-cyclohexyl-nitroso-urea). This evidence concerns the gene DIRAS3 and ovarian carcinoma.