Although significant correlation between CAIX and HIF-1α protein expression in tumours was observed (P = 0.013) (Table 2); further adjustments by age, grade, tumour size, lymph node stage and HIF-1α H score in survival outcomes of CAIX tumour expression, HIF-1α did not affect CAIX risks on poorer survival and prognostic outcomes ([DFS: HR = 2.95, 95% CI 1.75 to 5.00, P < 0.001], and [OS: HR = 2.43, 95% CI 1.34 to 4.41, P = 0.004]). The gene discussed is CA9; the disease is neoplasm.