CA9 and breast cancer: Acetazolamide combined with SFN treatment can significantly inhibit BC growth in vivo and in vitro, produce effective anti-proliferative and anti-cloning effects, induce cell apoptosis through activation of caspase-3 and PARP, and inhibit the EMT process of BC cells by downregulating the levels of CA9, E-cadherin, N-cadherin, and vimentin.