MAP3K15Mitogen-activated protein kinase kinase kinase 15 is a protein that in humans is encoded by the MAP3K15 gene.FunctionThe protein encoded by this gene is a member of the mitogen-activated protein kinase family. These family members function in a protein kinase signal transduction cascade, where an activated MAPK kinase kinase phosphorylates and activates a specific MAPK kinase, which then activates a specific MAPK. This MAP3K protein plays an essential role in apoptotic cell death triggered by cellular stresses.