NMUR1 and oropharynx cancer: Additional analysis that included only patients with oropharyngeal cancer (n = 75) revealed shorter DFS for methylated vs. unmethylated GHSR and NMUR1 (log-rank test, P = 0.004 and P = 0.008, respectively), but no differences for the other three genes (Additional File 8: Fig. S4c,d).