PTGS2 and esophageal squamous cell carcinoma: COX-2 is overexpressed in transformed cells and cancers of both the pharynx and gastrointestinal tract, including squamous carcinoma of the head and neck (Chan et al, 1999), colorectal carcinoma (Kutchera et al, 1996), gastric carcinoma (Ristimaki et al, 1997), Barrett's oesophagus and Barrett's adenocarcinomas (Wilson et al, 1998; Zimmermann et al, 1999; Morris et al, 2001), as well as ESCC (Ratnasinghe et al, 1999; Zimmermann et al, 1999; Shamma et al, 2000).