CA9 and cancer: Figure 5 summarizes data from the ToPP, which were acquired after the selection of The Cancer Genome Atlas–Breast Invasive Carcinoma (TCGA-BRCA) dataset. A univariate analysis of CA IX revealed a significantly elevated expression of the CA9 gene in tumor tissue (Figure 5A). Based on the expression status of CA9 (CA9 high/low), stage distribution as well as age at initial pathologic diagnosis are depicted in Figure 5B,C, respectively. Although not statistically significant, the OS according to the CA9 expression status is presented in Figure 5D.