Promising preclinical examples of targeted fluorescently labeled probes include anti carcinoembryonic antigen in pancreatic cancer and colorectal cancer conjugated to a green fluorophore (113), anti carbohydrate antigen 19-9 in pancreatic cancer conjugated to a green fluorophore (114), epidermal growth factor receptor (EGFR) and EGFR type2 (HER2) in breast cancer (195–197) and prostate-specific membrane antigen (PSMA) in prostate cancer conjugated to ICG (121). Here, FOLH1 is linked to colorectal cancer.