PTGS2 and cancer: In the last decade, several studies have indicated a link between the expression of COX-2 and the pathogenesis of several types of human cancers, including breast (Brueggemeier et al, 1999; Half et al, 2002), gastric (Ristimäki et al, 1997), lung (Hida et al, 1998) and colorectal adenocarcinomas (Eberhart et al 1994; Tomozawa et al, 2000).