Recent research has shown that the alteration of combinations in gene expression contributes to cellular phenotypic changes. Previously, it has been demonstrated that the combination of cadherin 1 and cadherin 2 expression can identify the diffuse-type and intestinaltype gastric cancers. Although the diffuse-type gastric cancer has been resistant to treatment, the precise mechanism and phenotypic involvement has not been revealed. It may be possible that stem cells transform into gastric cancer cells, possibly through the involvement of a molecule alteration and signaling mechanism. In this review article, we focus on the role of catenin beta 1(CTNNB1 or β-catenin) and describe the regulation of CTNNB1 signaling in gastric cancer and stem cells. Recent research has shown that the alteration of combinations in gene expression contributes to cellular phenotypic changes. Previously, it has been demonstrated that the combination of cadherin 1 and cadherin 2 expression can identify the diffuse-type and intestinaltype gastric cancers. Although the diffuse-type Gastric cancer has been resistant to treatment, the precise mechanism and phenotypic involvement has not been revealed. It may be possible that stem cell transform into gastric cancer cells, possibly through the involvement of a molecule alteration and signaling mechanism. In this review article, we Focus on the role of catenin beta 1 (CTNNB1 or β-catenin) and describe the regulation of CTNNB1 signaling in gastric cancer and stem cells.