CEACAM5 and non-small cell lung carcinoma: The mRNA expression of carcinoembryonic antigen-related cell adhesion molecule 5 (CEACAM5) has been also assessed in PB of patients with NSCLC [19,20,21]; however, contradictory results were shown regarding the detection frequency and clinical relevance of CEACAM5mRNA+ CTCs, whereas their kinetics during treatment has not been investigated so far.