IDH1 and central nervous system cancer: A subsequent retrospective cohort analysis conducted by Seliger et al. observed the opposite effect, as MFRMN was significantly associated with increased overall survival (OS) and progression-free survival (PFS) in grade III gliomas (n = 231 subjects), while no improvement was observed for the HGG subgroup (n = 862 subjects), supporting the hypothesis that IDH 1/2-MT status and a lower grade may increase the likelihood of response to metabolically active drugs (Table 1) [64].