These eight candidate antigens(TNC, ITGB1, CD44, GPNMB, SPARC, PFN1, HLA-DR/DQ/DP and CD133) wereherein immunophenotyped on EVs by IFCM, in combination with tetraspanins(CD81, CD63 and CD9), and quantified as double-positive EV subpopulationsin plasma samples from 22 healthy donors (HD), 41 newly diagnosedglioblastoma (GBM) patients, 37 matched postoperative (post-OP) and11 matched recurrent patients (relapse GBM). The gene discussed is CD81; the disease is glioblastoma.