CEACAM1 and lung adenocarcinoma: Although other CEACAM family proteins, such as CEACAM1 and CEACAM5, are known to be dysregulated in lung adenocarcinoma as well, CEACAM6 is more highly expressed than CEACAM5 and is associated with poor clinical outcomes among lung adenocarcinoma patients3,7,13–15,18,19.