PTGS2 and colorectal cancer: As well as colorectal cancer, increased COX-2 expression is found in carcinomas of various organs including the breast, prostate (Gupta et al, 2000), lung (Wolff et al, 1998), oesophagus (Zimmermann et al, 1999), pancreas (Tucker et al, 1999) and mucous membrane of head and neck (Chan et al, 1999).