To explore the impact of mutant IDH, as well as that of the 1p/19q co-deletion and the G-CIMP status, on alternative splicing in gliomas, we undertook an investigation of the transcriptome RNA sequencing (RNAseq) data of a cohort of 662 diffuse gliomas (see Materials and Methods, Section 4.1) contained in The Cancer Genome Atlas (TCGA, https://cancergenome.nih.gov/, accessed on 6 September 2022)) [32]. The gene discussed is IDH1; the disease is central nervous system cancer.