Particularly, the MFE-23 scFv has been shown to effectively target CRC in imaging and antibody-directed pro-drug therapy strategies, due to its enhanced tumor cell internalization, prolonged half-life (superior to 4 days at 37 oC), and presence of a binding domain for anti-CEA immunotoxins [24, 25]. Here, CEACAM5 is linked to colorectal carcinoma.