CD63 and neoplasm: We have set up an immunocapture-based ELISA (Enzyme-Linked Immuno Sorbent Assay) test through which it has been shown that melanoma patients have significantly increased plasmatic levels of exosomes, particularly those expressing a surrogate tumour marker such as CAV-1 (Caveolin-1), as compared with the plasma of healthy donors [26] but also analysing those simply expressing a housekeeping exosomes marker such as CD63 [27].