HIF1A and neoplasm: After accounting for age, grade, tumour size and lymph node stage, there is a statistically significant association in patients with both HIF-1α and CAIX protein co-expression and survival outcomes ([DFS: HR = 4.46, 95% CI 2.26 to 8.81, P < 0.001], and [OS: HR = 3.30, 95% CI 1.57 to 6.94, P = 0.002]) (Table 3).