Fig. 4

a Co-mutation map showing alterations in genes involved in the Notch pathway in 19 (32 %) oral tongue squamous cell carcinoma (OTSCC) samples. Gene names and mutation rates are as indicated on either side of the plot, while the type of mutation follows the legend below. b, c Comparison between OTSCC, oral cavity cohort from TCGA (OC-TCGA) and entire head and neck cohort of TCGA (HN-TCGA) for NOTCH1 mutation frequency and alterations in the entire Notch pathway (11 genes), respectively. P value based on t-test as indicated if significant or NS if not significant. d Kaplan-Meier plot showing DFS estimates according to the mutational status of the Notch pathway. P value is based on log-rank test. e Results of multivariate analysis of selected prognostic factors for DFS in OTSCC by Cox proportional hazards model. HR hazard ratio