CP 43 is a potent TAO kinase (TAOK) inhibitor (IC50 values are 11 nM/L and 15 nM/L for TAOK1 and TAOK2, respectively). Inhibits TAOK phosphorylation and activation of JNK in vitro. Also prolongs duration of mitosis and increases mitotic cell death in the SKBR3 breast cancer cell line.