IDH1 and cancer: In multivariable regression analysis with study (TCGA‐COADREAD, S:CORT or DFCI) as a random effect, CIMP was independently associated with IDH mutation (OR = 1.63; 95% CI = 1.27–2.09; p = 1.3 × 10−4), MSI (OR = 1.51; 95% CI = 1.40–1.62; p < 2 × 10−16), age at diagnosis (OR = 1.004; 95% CI = 1.002–1.006; p = 3.2 × 10−4) and proximal cancer location (OR = 1.32; 95% CI = 1.26–1.38; p < 2 × 10−16).