BIX02189 is a selective inhibitor of MEK5 with IC50 of 1.5 nM, also inhibits ERK5 catalytic activity with IC50 of 59 nM in cell-free assays, and does not inhibit closely related kinases MEK1, MEK2, ERK2, and JNK2. *For Research & Development use only. Product is not intended for drug, household, or human consumption.