CEACAM5 and neoplasm: To evaluate whether specifically targeting CRC cells inhibited Wnt signaling, mRNA from LS174T tumors in different treatment groups was extracted and analyzed via qRT-PCR, and it was found that the use of pep1-Max-CEABP1 to target CEA-expressing CRC cells and deliver TCF/LEF TFD DNA indeed caused higher suppression of Wnt responsive genes such as axin2 and c-myc in the tumor tissue compared to pep1-Max (Figure 9E).