Updated project metadata. Updated publication reference for PubMed record(s): 30627607. Ovarian cancer is the most lethal gynecological malignancy, because its early detection is difficult due to the absence of recognizable physical symptoms and a lack of sensitive screening methods. Despite a large number of proteomic studies of biological fluids from ovarian cancer patients, only a few biomarkers are used in clinical practice. Low molecular weight endogenous peptides more easily diffuse across endothelial barriers and can be more relevant biomarker candidates. In this current study, detailed peptidomic analysis of 26 ovarian cancer and 15 non-cancer samples of biological fluids (ascites and sera) were performed using TripleTOF 5600+ mass-spectrometer.