PROBLEM TO BE SOLVED: To provide a new protein and its gene associated with activation of p38 mitogen-activated protein (MAP) kinase. SOLUTION: This protein is the following (a) or (b). The gene encodes the protein (a) or (b). (a) The protein is composed of a specific amino acid sequence. (b) The protein is composed of the amino acid sequence or another specific amino acid sequence in which one or more amino acids are substituted, deleted, inserted and/or added and has properties of activating the p38 MAP kinase. COPYRIGHT: (C)2003,JPO