CHRNA5 and cancer: To determine the possible mechanism by which CHRNA5 upregulation/activation confers radioresistance on OSCC cells, we analyzed the coexpression of CHRNA5 and other somatic genes in TCGA OSCC subcohort with high CHRNA5 transcript levels and cancer recurrence in the Kaplan–Meier analysis, by performing an in silico analysis using the gene set enrichment analysis (GSEA) software (Figure 4A).