In recent studies, serum VEGF levels outperformed conventional cancer biomarkers like carcinoembryonic antigen (CEA), cancer antigen–125 (CA–125), and cytokeratin 19 fragments (Cyfra 21-1) in the early diagnosis and severity assessment of non-small cell lung cancers and ovarian cancer and also as a predictive biomarker for treatment response and prognosis in breast cancer [5,6,7]. Here, CEACAM5 is linked to ovarian cancer.