Studies have demonstrated that the transcription and secretion of CEA are regulated by the Smad3-mediated tumor growth factor and transforming growth factor β (TGF-β) signaling pathway, and TGF-β plays an important role in cell proliferation and differentiation, embryonic development, extracellular matrix formation, immune regulation, and tumor development 19. The gene discussed is CEACAM5; the disease is neoplasm.