CEACAM5 and colorectal cancer: We were able to observe that a lower percentage of I-C19-treated mice developed colorectal adenocarcinomas compared to mice treated with the vehicle or C19 (Figure 7A), suggesting that I-C19 decreases the activation of K-Ras4B in vitro and in vivo and that the radiation delivery system through C19 to colon cancer cells is efficient, as it also reduces CEA (Figure 7C; upper panel) and Ki67 staining (Figure 7C; lower panel), which allowed us to confirm that this treatment decreased the malignancy and proliferative capacity of colorectal cancer with mutated K-Ras4B.