MKI67 and Barrett esophagus: Pairwise mean comparisons found the percentages of MCM4, MCM7, and Ki-67 expression in esophageal adenocarcinoma and high-grade dysplasia to be significantly greater than those in low-grade dysplasia, Barrett's esophagus, columnar cell metaplasia, and squamous epithelium (P < .05) (Table 1).