CEACAM5 and cancer: For example, a hypothetical 70-year-old female and nonsmoker patient who has a peripherally RUL located squamous NSCLC, 2 cm in diameter and no suspected positive lymph nodes thus clinically staged as cT1aN0 IA, also absent of history of cancers but present with family history of cancer and history of other lung disease, and serum CEA of 80 ng/mL, we calculate a score of −5.75, and therefore the predicted probability of N2 lymph nodes metastases is 0.5%, which is low enough for the patient to go directly to surgery without further invasive diagnostic tests.