Obesity increases the risk of ovarian cancer, which some evidence suggests may be due to chemicals, such as estrogen, secreted by fat tissue into the blood. Dr. Klopp, however, believes fat cells directly affect tumor growth because they contain stem cells, or self-renewing cells, which can migrate into nearby tumors and support the tumor cells’ growth. Recently, Dr. Klopp isolated stem cells from human omentum, the fatty tissue to which ovarian cancers often metastasize, and in preliminary studies showed these stem cells support the growth and invasion of ovarian cancer cells. In this study, Dr. Klopp will determine if these stem cells migrate into ovarian tumors and increase tumor growth in mice implanted with human ovarian cancer cells. She also will isolate more stem cells from the omentum of patients and determine if these cells help proliferate and spread tumors. Finally, she aims to identify the aberrant molecular pathways that cause the tumor promoting effects in these stem cells. Her findings should increase understanding of obesity’s role as an ovarian cancer risk factor, shed light on why tumors metastasize to the omentum and lead to possible drugs that could block stem cells’ effects on tumor growth and spread.