None-malignant cells contribute to DcR3 in EOC. DcR3 levels were determined by ELISA and values compared to media devoid of cells. A. DcR3 is not produced by the EOC cell lines tested as compared to the colon cancer cell lines SW626 and SW480. B. DcR3 is produced by primary culture of peritoneal cells (mix of cells including immune cells, stromal cells, mesothelial cells, and tumor cells) from women with ovarian cancer and the level in culture correlates to the levels in the patient’s ascites fluid (data not shown). C-D. Cells that adhere to plastic in one hour or less (Pt#-1) produce as much or more DcR3 than cells that were allowed 24 h to adhere (Pt#-2). D. Rapidly adherent cells produce as much or more DcR3 however have 50-95% fewer cancer cells than the 24 h samples. E. Primary culture of peritoneal cells from patients with none-malignant ascites produce DcR3 (DcR3 is also present in the ascites fluid at levels similar to the malignant ascites of ovarian cancer, data not shown). Taken together these results suggest that non-malignant cells contribute to the DcR3 levels seen in the peritoneal cavity in advanced EOC.