In statistical analysis comparing clinicopathological variables with CA IX expression (Table 2), the tissue CA IX (tCA IX) positivity significantly correlated with tumor grading (p = 0.0146), necrosis (p = 0.0015), the ER status (p = 0.0019), and with molecular subtypes of BC (p = 0.0115). This evidence concerns the gene ESR1 and breast cancer.