CD63 and neoplasm: Alternatively, we propose that a targeted anti-GFP EV-CATCHER assay, although not biologically relevant to EVs (i.e., not targeting common EV tetraspanins), could be used in future studies to increase specific selection of exhaled human tumor-derived EVs produced by CD63-GFP+ LM-3475 cells, along with GFP fluorescent signal detection to further confirm the identity and origin of CD63-GFP+ tumor EVs.