PROBLEM TO BE SOLVED: To provide a neuritis or demyelinating disease preventive or therapeutic pharmaceutical composition.SOLUTION: A neuritis or demyelinating disease preventive or therapeutic pharmaceutical composition comprises Dock8 protein or DNA coding for the protein.【課題】神経炎症又は脱髄疾患の予防又は治療用医薬組成物の提供。【解決手段】Dock8タンパク質又は該タンパク質をコードするDNAを含む、神経炎症又は脱髄疾患の予防又は治療用医薬組成物。【選択図】なし