CA9 and invasive breast carcinoma: An IHC-based tissue microarray study of invasive breast cancer patients (n = 276) evaluating metabolism-related proteins according to the molecular subtype, demonstrated that the expression of IGF-1, MIF, and HIF1A was correlated with the HER2-enriched subtype, while Glut-1 and CAIX expression were associated with triple-negative subtype, high histologic grade, and HR-negativity (Choi et al., 2013).