 After obtaining informed consent, blood will be obtained and subjects will proceed with their routine care upper endoscopy. The endoscopist, as per routine practice, will note findings in the procedure report and photograph or record video to confirm and document key findings, as well as take biopsies as indicated for routine care. During the procedure up to 10 research biopsies will be collected as part of this study. Research biopsies will be collected in addition to routine care biopsies and will be obtained with a standardized biopsy protocol below. The total number of research biopsies may vary based on presenceabsence of nodularity but will not exceed 10 research-specific biopsies. This number of esophageal biopsies is within the standard of care for biopsying the esophagus. 