Similarly, studies also indicated that the expression of serum CEA is associated with bone metastasis in NSCLC (Li et al., 2016; Noris-Garcia & Escobar-Perez, 2004; Reiber, 2001; Reiber, Jacobi & Felgenhauer, 1986). The gene discussed is CEACAM5; the disease is non-small cell lung carcinoma.