RARB and gastric carcinoma: Methylation in the promoter region of RAR-β gene is frequently found to be associated with downregulation/loss of its expression in tissues affected with gastric carcinoma and in gastric cell lines, head and neck cancers, breast cancer and non-small-cell lung carcinoma (Xu et al, 1994, 1997; Hayashi et al, 2001; Oue et al, 2002).