PTGS2 and esophageal squamous cell carcinoma: BE and ESCC groups also presented significant higher percentage of COX-2 positive cells, when compared to esophageal samples from obese individuals, whereas no significant differences were detected among BE, EAC and ESCC groups, although it is possible to observe a lower percentage of COX-2 positive cells in ESCC samples, when compared to BE and EAC samples (Fig. 4B).