Microvesicles play essential roles in disease progression. The present invention provides a novel microvesicle membrane protein and application thereof. Disclosed is method comprises phosphorylated CSE1L (cellular apoptosis susceptibility protein)- or CSE1L-binding agents for microvesicle isolation, analysis, or binding for disease diagnosis or treatment.細胞微泡與疾病有關,本發明涉及一個新發現的磷酸化CSE1L(染色體分離-1類蛋白,chromosome segregation 1-like protein)微泡膜蛋白及其應用。所揭示包含可與CSE1L或磷酸化CSE1L結合的組合物,用於分離、檢測或結合微泡,應用於疾病診斷或治療。