IDH1 and central nervous system cancer: Patient 52 with IDH-mutant-codel glioma received BEV treatment after tumor recurrence, the first post-treatment cf-tDNA sample at 2 months showed molecular remission, while the second cf-tDNA sample at 4 months was detected to have MMR mutations (highest VAF 9.3%) with 184 somatic mutations, and the tumor disseminated toward other regions as well (Figure 3G).