In Kaplan Meier survival analysis, a high score for the two-protein combined expression in the TC was significantly associated with worse OS (P = 0.003) and DFS (P = 0.035) (Fig 1B and 1C). However, no significant survival difference was seen between high and low groups for expression in the TP (OS, P = 0.208 and DFS, P = 0.748; Fig 1D and 1E, respectively). In univariate Cox regression analysis, a high two-protein combined status in the TC (combined TC high versus low: HR = 1.944, 95% CI 0.037–3.645, P = 0.038) was significantly associated with reduced DFS (Table 3). In multivariate Cox analysis (adjusted for combined expression of ATM and MRE11, and perineural invasion), the two-protein combination panel (HR = 2.178, 95% CI 1.115–4.256, P = 0.023) as well as perineural invasion (HR = 2.183, 95% CI 1.222–3.899, P = 0.008) remained significantly associated with DFS (Table 3).