p38 MAP kinase is the mammalian homologue of the yeast HOG kinase and participates in a cascade controlling cell cellular responses to cytokines and stress. Like the SAPK/JNK pathway，p38 MAP kinase is activated by a variety of cellular stresses including inflammatory cytokines，UV light and growth factors，etc. Activated p38 MAP kinase has been shown to phosphorylate and activate MAPKAP kinase-2 and to phosphorylate the transcription factors ATF-2 and Max.
