CEACAM5 and neoplasm: Such serum biomarkers include carcinoembryonic antigen (CEA), carbohydrate antigen 199 (CA199), carbohydrate antigen 125 (CA125), neuron-specific enolase (NSE), lactate dehydrogenase (LDH), etc. The potential of exploiting quantified levels and mutational load of cfDNA to monitor tumor burden in CRC patients has also been reported in a few studies [7, 8].