Residual embryonic cells in human tissues
A. Immunofluorescence imaging of section of human 21-week-old esophagus showing suprasquamous distribution of Krt7 (green), Muc4 (green), and Krt5 (red). These results were consistent in the three independent fetuses tested. B. Expression of Krt7 (green), Krt5 (red), and Muc4 (green) cells in section of gastroesophageal junction from adult human without Barrett's esophagus. This result was consistent in the sections from three individuals tested.