Importantly, aberrant and mislocalized expression of MUC5AC mucin in adenomas and carcinomas has been reported (Bartman et al., 1999; Sylvester et al., 2001; Bryant and Stow, 2004), as well as modification of mucins glycosylation patterns during colonic carcinogenesis (Devine and McKenzie, 1992; Itzkowitz et al., 1992; Mann et al., 1997; Jenab et al., 2001; Mesquita et al., 2003). This evidence concerns the gene MUC5AC and adenoma.