MAFF and Barrett esophagus: In our previous study on human Barrett's esophagus, a metaplastic condition in which the stratified squamous epithelium of the lower esophagus is replaced by intestinalized columnar epithelium, we found that several transcription factors such as Nrf2 (nuclear factor erythroid derived 2 like 2, or Nfe2l2) and small Maf proteins (MafF, MafG) were enriched in the normal human esophagus as compared with Barrett's esophagus [11].