The overall aim is to identify effective therapeutic strategies to ovarian cancer (OC) using serial tumor, ascites and blood samples, and carry out state-of-the-art sequencing approaches, functional assays and associated bioinformatics to understand mechanisms behind chemoresistance in OC and identify new treatment options for OC patients. In this observational trial, we will systematically collect, analyze and interpret functional, molecular and clinical data from real-world ovarian cancer patients.