These proteins include both EV markers (CD9, CD63 and CD81), proteins that can indicate the cellular origin (e.g. CD3, CD4, CD8, CD14, CD41b, CD42a, CD45 and CD62p), cell activation markers (e.g. CD44, platelet activation marker CD62P (P-selectin)), antigen presenting proteins (HLA-DR/DP/DQ) and cancer-related markers (CD24, CD29, CD44 and CD146). Here, CD9 is linked to cancer.