 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 targets specific transcription factors, and thus mediates immediate-early gene expression in response to various cell stimuli.It is most closely related to MAPK8, both of which are involved in UV radiation-induced apoptosis, thought to be related to the cytochrome c-mediated cell death pathway.