PURPOSE: Evidence exists that dysregulation of apoptosis is involved in the pathogenesis of cancer development. Fas- associated death domain (FADD) protein, an adaptor protein of death receptors, is a critical regulatory component of the extrinsic cell- death pathway that exerts its pro-apoptotic effect upon binding with death receptors. Expression of the FADD protein has not been reported in stomach cancer. The aim of this study was to explore the expression status of the FADD protein in stomach cancers. MATERIALS AND METHODS: In the current study, we analyzed the expression of the FADD protein in 60 advanced stomach cancer by using immunohistochemistry and a tissue microarray approach. RESULTS: Immunopositivity (defined as > or =30%) was observed for the FADD protein in 23 (38%) of the 60 cancers. Normal gastric mucosal cells showed expression of the FADD protein. CONCLUSION: Taken together, these results indicate that decreased expression of the FADD protein is a frequent event in stomach cancers and suggest that to avoid apoptosis, stomach cancer cells in vivo may need loss of FADD expression, which might contribute to tumor development.