Inclusion Criteria:  Patients ≥18 years of age or adults according to age of majority as defined by the local regulations; Willing and able to provide written informed consent for participation in the study; Patients with histologically confirmed new diagnosis (within past 120 days of enrolment) of high-grade (stage III or IV of FIGO classification 2014) serous or endometrioid ovarian, primary peritoneal, and/or fallopian tube cancer; Patients having availability of histopathology report and FFPE archival tumour tissue block(s) collected within past 120 days of enrolment.  Exclusion Criteria:  Patients with mucinous, clear-cell, undifferentiated carcinoma or malignant Brenner's tumour; Patients diagnosed with any severe acute or chronic medical or psychiatric conditions that may increase the risk associated with study participation or may interfere with the interpretation of the study results, and those in the judgment of the investigator are not appropriate for enrolment in this study