For example, for GC [79], the HOXA transcript at the distal tip (HOTTIP) in exosomes isolated from the serum may serve as a biomarker with higher diagnostic value than common tumor markers currently used in serum, such as carbohydrate antigen (CA) 19–9, CA 72–4, and carcinoembryonic antigen (CEA). Here, CEACAM5 is linked to neoplasm.