CA9 and neoplasm: Here, using a highly metastatic, in vivo model of CAIX-positive human TNBC, we demonstrate that the administration of a clinically validated inhibitor of CAIX activity, SLC-0111, dramatically reduces spontaneous metastases, whereas the decrease in tumor growth, while evident, is more modest, suggesting that the reduction in metastasis observed with inhibition of CAIX is not due solely to reduced tumor growth.