According to the current clinic upper limit of normal concentration, only 1 out of 11 NSCLC patients has a CEA level higher than 5 ng/mL, while all non-NSCLC patients had CEA levels lower than 5 ng/mL (Figure 8A), indicating that this upper limit is not effective for aiding in the diagnosis of NSCLC. The gene discussed is CEACAM5; the disease is non-small cell lung carcinoma.