MEK1 is also named as MAP2K1 (mitogen-activated protein kinase kinase 1), MAPKK1, PRKMK1, MKK1 and belongs to the MAP kinase kinase subfamily. It is a dual-specificity kinase that mediate ERK1 and ERK2 activation during adhesion and growth factor signaling. It also plays an essential role in extra-embryonic ectoderm during placentogenesis. MEK1 has 2 isoforms produced by alternative splicing with the molecular weight of 43 kDa and 41 kDa. It can be phosphorylated. This antibody is specific to MEK1.