When time to recurrence was introduced, in addition to age, tumor size, HPV status, and disease stage, in multivariate models to assess whether HIF-1α +/− CAIX over-expression has an independent prognostic meaning, statistical significance was lost (HR: 1.22, 95% CI: 0.88–1.7, p = 0.223). The gene discussed is CA9; the disease is neoplasm.