HIF1A and neoplasm: We also observed a correlation between overexpressed HIF-1α with poor histological differentiation in 10 studies (1324 patients) because the pooled ORs (95% CI) were 2.112 (1.410–3.163, P<0.001) and the tumor size was 1.921 (1.395–2.647, P<0.001), but not for sex (0.905; 0.679–1.205, P = 0.495) and age (0.846; 0.667–1.072, P = 0.166), among all Asian patients (Table 2).