PURPOSE:To provide a mouse lacking a function of endoserine-1 gene. CONSTITUTION:This invention is a mouse in which the function of endoserine-1 gene is removed by inserting another gene into the endoserine-1 gene. This mouse is useful, e.g. for clarification of the pathologic physiology and the cause of circulatory diseases such as hypertension, arteriosclerosis and ishemic heart disease and for development of the therapy.