Results from qPCR analysis using human tissue cDNA arrays (Table 2) showed that full-length CEA transcript was commonly detected (Ct≤30) in pancreatic adenocarcinomas (4 of 5), colon (41 of 42), gastroesophageal (38 of 42), lung (39 of 40), and breast cancers (38 of 41) of various grades and stages. Here, CEACAM5 is linked to breast carcinoma.