EPCAM and lung cancer: We then fractionated exosomes from lung cancer patients and healthy controls into four groups: exosome‐all (total exosomes), exosome‐ΔEpCAM (depleted with anti‐EpCAM), exosome‐ΔEpCAM+Spike (reconstituted with captured EpCAM+ exosomes), and exosome‐IgG (isotype antibody control).