XMD8-92 is highly selective ERK5/BMK1 inhibitor (KD values are 80, 190, 600 and 890 nM for BMK1, DCAMKL2, PLK4 and TNK1 respectively). XMD8-92 displays selectivity over 402 diverse kinases. XMD8-92 blocks growth factor-induced activation of cellular BMK1 and reduces BMK1 activity in in vitro kinase assays. XMD8-92 also reduces BMK1-dependent transactivating activity of MEF2C. XMD8-92 inhibits proliferation in a variety of cancer cell lines; blocks tumor cell proliferation and tumor-associated angiogenesis.