CEACAM5 and neoplasm: Especially, the NSCLC-derived exosomes from tumor cells (e.g., A549, H460, and H1299) carry different expression levels of multitudinous proteins (e.g., epithelial cell adhesion molecule (EpCAM) and carcinoembryonic antigen (CEA)), resulting in distinct surface phenotypes correlated with cancer occurrence and progression [20–22].