CDH17 and colorectal carcinoma: It showed significant higher TBR signals at 12 h than Con-PE38Mut-IR800CW and retained the high TBR until 24 h, whereas nontargeted Con-PE38Mut-IR800CW did not exhibit any specific accumulation in tumors besides liver areas and signals almost disappeared 24 h after drug administration, manifesting that CDH17-targeting Nb E8 could deliver the PE38 toxin into CRC tumors specifically and efficiently (Fig. 5A and C).