Both CAIX and HIF1A expression were having a strong correlation with histopathological grade (coefficient correlation (r) ranged from 0.7 to 0.8, p < 0.0001), but neither associated with tumor type (LABC or MBC), age, nor age group (< 40 years and ≥ 40 years) (Table 3). The gene discussed is CA9; the disease is neoplasm.