A human pancreatic adenocarcinoma was used to develop two histologically distinct xenograft lines, one associated with high levels (180-2000 ng ml-1) and one with low levels (greater than 2.0 less than 8.0 ng ml-1) of serum carcinoembryonic antigen (CEA). Here, CEACAM5 is linked to pancreatic adenocarcinoma.