In this study, the investigators are studying new ways to look for abnormal tissues of the gastrointestinal tract during an endoscopy. We are using a VEGF-A targeting fluorescent probe and a NIR-II fluorescent endoscope to help detect abnormal tissues that are hard to see by the naked eye.

The main purposes of this study include:

1. To translate the NIR-II approach into the endoscopy, and understand its advantages and limitations on detecting abnormal tissues in gastrointestinal.
2. To validate whether topical administration of a targeting probe can stick to abnormal tissues and be detected by the NIR-II endoscope.
3. To validate the safety and effectiveness of the topical administration of VEGF-A targeting probes for clinical application.

Inclusion Criteria:

• Known or suspected gastrointestinal lesions.
• Scheduled for a clinically-indicated endoscopy.
• Mentally competent person, 18 years or older.
• Approved to sign the informed consent.
• Adequate potential for follow-up.

Exclusion Criteria:

• Subjects with known allergy or negative reaction to ICG or derivatives.
• Undesirable function of heart, lung, kidney, or any other organs.
• Enrolled in other trials in the past 3 months.
• Pregnant or trying to conceive.
• Unable to tolerate an endoscopy.
• Medical or psychiatric conditions that compromise the patient's ability to give informed consent.
• The researchers considered inappropriate to be included.