This report documents that the pancreatic adenocarcinoma cell line, HPAF, contains oncogene activity detected by transformation of NIH 3T3 cells through transfection with HPAF DNA. The HPAF transfected NIH 3T3 cells do not contain oncogenes homologous with c-H-ras, c-K-ras, c-N-ras, v-fms, c-myb, c-sis, v-fgr, c-mos, c-myc, c-fos, v-fes, v-src, v-erb A, v-erb B, c-N-myc, v-raf, or v-abl, other than the endogenous mouse genes. The transfectants do express proteins detected by two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis which were not found in nontransfected NIH 3T3 cells. Monoclonal antibodies raised against the transfectants recognize proteins not found in untransfected NIH 3T3 cells that are antigenically identical to proteins found in the HPAF cells. These antigens are also detected on six other human pancreatic adenocarcinoma cell lines but show a much more restricted distribution on lymphoblastoid, melanoma, prostatic carcinoma, and normal skin fibroblast cell lines.