This is a single-institution, non-interventional prospective observational study allowing for specimen and data collection. All participants will receive standard of care surgery and chemotherapy, determined by the gynecologic oncologist and per institutional protocols. Patients with a presumed diagnosis of an eligible gynecologic malignancy (epithelial ovarian, fallopian tube, primary peritoneal, or uterine endometrial cancer) who are being considered for neoadjuvant chemotherapy prior to confirmatory biopsy will be given the option to enroll on this study.