Background：

The protein encoded by this gene is a member of the MAP kinase family. MAP kinases act as an integration point for multiple biochemical signals， and are involved in a wide variety of cellular processes such as proliferation， differentiation， transcription regulation and development. This kinase is activated by various cell stimuli， and targets specific transcription factors， and thus mediates immediate-early gene expression in response to cell stimuli. The activation of this kinase by tumor-necrosis factor alpha (TNF-alpha) is found to be required for TNF-alpha induced apoptosis. This kinase is also involved in UV radiation induced apoptosis， which is thought to be related to cytochrom c-mediated cell death pathway. Studies of the mouse counterpart of this gene suggested that this kinase play a key role in T cell proliferation， apoptosis and differentiation. Several alternatively spliced transcript variants encoding distinct isoforms have been reported.?