The mitogen-activated protein/ERK kinase kinase 3(MEKK3) is a member of a family of MEKK/Ste11 serine/threonine protein kinases. One function of MEKK3 is to serve as an upstream regulatory kinase in the mitogen-activated protein kinase cascade, however, it also plays a critical role in other signaling pathways. MEKK3 regulates several important functions including cell survival and proliferation. It is ubiquitously expressed in multiple tissues and has been found in complexes with scaffold proteins and other kinases.(PMID: 18206350).Cerebral cavernous malformations(CCMs) complex regulation of MEKK3 is essential during vertebrate heart development. MEKK3 signalling and KLF2/4 may be targeted to develop new CCM therapeutics.