CD39 expressing M2 macrophages are elevated in the peritoneal fluid of patients with metastasis of gastric cancer

Background: A critical immunoregulatory pathway in the tumor microenvironment (TME) involves CD39 and related cell-surface located enzymes that regulate the hydrolysis of extracellular, pro-inflammatory ATP and generate immunoregulatory adenosine. In gastric cancer, CD39 is upregulated and associated with worse survival, but little is known about the role of CD39 in peritoneal metastasis. In this study, we investigate immune cell expressed CD39 in peritoneal fluid as part of the TME of peritoneal metastasis derived from gastric cancer.