CEACAM5 and non-small cell lung carcinoma: Among 30 NSCLC patients with PR, there were 26 cases with reduced SP70 level (86.7%), 25 cases with reduced CEA level (83.3%), 21 cases with reduced CYFRA21‐1 level (70%), and 10 cases with reduced NSE level (33.3%) (χ2 = 24.801, P < .001).