IDH1 and central nervous system cancer: According to the phenotypes and genotypes (27, 28), based on mutation of the IDH1 and IDH2 genes and codeletion of chromosomes 1p and 19q, lower-grade gliomas can be classified as three molecular subtypes: IDH wild type (IDHwt), IDH mutant with 1p/19q codeletion (IDHmut-Codel) or IDH mutant with no 1p/19q codeletion (IDHmut-Noncodel) (29).