Yet, high pretreatment carcinoembryonic antigen (CEA), neutrophil–lymphocyte ratio (NLR), platelet–lymphocyte ratio (PLR), and low lymphocyte–monocyte ratio (LMR) are tightly associated with poor prognosis of non-small-cell lung cancer (NSCLC) (Chen et al. 2018; Grunnet and Sorensen 2012; Kuo et al. 2020). Here, CEACAM5 is linked to non-small cell lung carcinoma.