This gene encodes a serine-threonine protein kinase that is activated by extracellular signal-regulated kinase or p38 mitogen-activated protein kinases, and it may function in cytokine and environmental stress responses. This kinase is required for phosphorylation of eukaryotic translation initiation factor 4E but it is not required for cell growth during development. Alternative splicing of this gene results in multiple transcript variants. [provided by RefSeq, Oct 2013]