CDC25B and breast carcinoma: Interestingly, a previous study reported that the compound CHEQ-2 not only inhibited CDC25A and CDC25B catalytic activity in vitro, but also caused down-regulation of CDC25A and CDC25B at doses higher than ~15 μM in human colon cancer (HT-29), breast cancer (MCF-7), and hepatocellular carcinoma (HepG2) cells (29).