MEK inhibitor is a tyrosine kinase receptor and cell cycle protein/CDK complex inhibitor with antitumor activity and can be used to study tumor cell proliferation.

MEK inhibitor is a potent inhibitor of MEK (mitogen-activated protein kinase), a kinase responsible for phosphorylating MAPKs (mitogen-activated protein kinases), and activated MAPKs further phosphorylate downstream transcription factors to regulate a variety of biological responses, including stress signaling, pathogen response, and hormone signaling. Inhibition of MEK leads to inhibition of MAPK phosphorylation and inhibition of biological responses downstream of MAPK. [1]