NTRK1 and Friedreich ataxia: Here, with the further inclusion of 4 additional signaling pathways (the receptor tyrosine kinase (RTK) signaling, DNA repair, Fanconi anemia (FA), and ROBO–SLIT pathways) and 3 key biological machineries relevant for HNC tumorigenesis (immune evasion, epigenetic, and metabolic regulatory machineries), we found that nearly all TCGA-HNC tumors (99.4%, 507/510) harbored mutations of at least one of the 14 pathway/machinery genes (Figure 3A; Table S5).