CEACAM5 and neoplasm: Early studies, such as those by Morse et al., Sebastian et al., and Papachristofilou et al., were conducted without advanced molecular profiling, as they investigated tumor-associated antigens, e.g., CEA, NY-ESO-1, MAGE-C1, and MUC-1, typically overexpressed in tumors, but also detectable at low levels in some healthy tissue [18,22,31].