Potential patients will be recruited at participating sites based on routine care with clinical indications for upper endoscopy. Following informed consent, patients will undergo their scheduled endoscopy with standard forceps biopsies along with the transepithelial brush samples. All samples, biopsy and brush samples, will be sent for pathology analysis, per standard clinical practice.

Potential patients will be recruited at participating sites based on routine care with clinical indications for upper endoscopy. Following informed consent, patients will undergo their scheduled endoscopy with standard forceps biopsies along with the transepithelial brush samples. All samples, biopsy and brush samples, will be sent for histologic analysis, with planned study of the diagnostic yields of each method.

Inclusion Criteria:

• Subject is informed of the investigational nature of this study and given verbal and written informed consent in accordance with local, U.S., and international guidelines.
• Both males and females at least 18 years.
• Patients with clinical indications for upper endoscopy

Exclusion Criteria:

• Patients should not have an advanced medical or psychiatric conditions which that may limit their ability to participate in the study, as judged by the physician.

Patients with indications for upper endoscopy (e.g. dyspepsia)