So Barrett's esophagus happens from chronic reflux disease. What happens is the acid washes up into the esophagus and causes a cellular change so that the normal esophogeal mucosa changes into more of a gastric mucosa and over time that can develop into what's called Barrett's esophagus and over time that can develop cell line becoming more cancerous so they go from normal to dysplasia to cancer. So it's considered a precancerous lesion due to reflux disease. Dysplasia is basically when normal cells are progressing towards developing cancerous cells. So it's not cancer per se, but it's different grades. You can go from low grade to high grade to cancer. So it's basically a progression of cell line change from normal to inflammatory to precancerous to cancer. Barrett's esophagus is consider a precancerous lesion once you start developing dysplasia within that cell line.