Homozygous deletions in these genes co-occur with IDH1 mutations in glioblastoma patients (Figure 5, Fisher test P-value < 0.0001 for the 14 different CNAs, co-occurrence odds ratio > 10), and to a lesser extent in lower grade glioma (co-occurrence odds ratios 2–10 for 10 CNAs, but not significant), but not in uterine, breast, ovarian, head and neck, lung, colon or kidney cancer patients (Supplementary Figure S9). Here, IDH1 is linked to central nervous system cancer.