Identification of CEACAM5 transcripts in pancreatic, gastric and colorectal cancer cells. Electrophoresis images of RT-PCR are shown in the left panel. RT-PCR of ACTB was used as a positive control. Schematic diagram of exon structures corresponding to the detected amplicons are represented in the right panel. Novel variant 5D (ii) skipped exons 3 and 4 of full-length transcript NM_004363 (i). Novel variant 3D (iii) contained novel alternative splice forms (gray boxes), and skipped exons 4–6 in (i). Primer positions for RT-PCR are indicated by black arrows.