Procarbazine, which is administered together with lomustine (1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea: CCNU, Gleostine) and vincristine (Oncovin) in the PCV scheme, is considered to be first-line therapy in IDH-mutant glioblastoma [11]. The gene discussed is IDH1; the disease is glioblastoma.