This colocalization of signals validated the specificity of CEA-FSNs.This indicates that CEA-FSNs specifically target CEA-expressing tissueand do not exhibit nonspecific binding to healthy tissues making themthe ideal particle to use for this application especially when comparedto nonantibody-conjugated FSNs.21 The ex vivo imaging results support the use of CEA-FSNs as areliable and precise molecular imaging agent, diagnostic, and targetedtherapy for CRC. The gene discussed is CEACAM5; the disease is colorectal carcinoma.