IDH1 and glioblastoma: These results are in concordance with a phase I/II trial (NCT01891747, https://clinicaltrials.gov/study/NCT01891747, accessed on 27 October 2024) whose phase I results showed a 25% increase in DNA methylated CpGs in tumor autopsies compared with the paired initial recurrent glioblastoma IDH-wildtype tumors [179]; nevertheless, the clinical efficacy of adding folate is yet to be determined.