title: Circadian CEA variability: when to sample.
mesh_terms: D002272:Carcinoembryonic Antigen / Q000032:analysis*; D002940:Circadian Rhythm; D006801:Humans; D009369:Neoplasms / Q000097:blood*; D012016:Reference Values
chemical_list: D002272:Carcinoembryonic Antigen