Outcome Data Sources
Summary-level data for OC were obtained from the Ovarian Cancer Association Consortium (OCAC), which involved 25,509 cases of overall OC and 40,941 controls of European descent [31]. In the subtype analyses, the data included 7 well classified OC histotypes: High grade serous (HGSOC, 13,037 cases and 53,978 controls), Low grade serous (LGSOC, 1,012 cases and 41,953 controls), Invasive mucinous (IMOC, 1,417 cases and 42,358controls), Endometrioid (EOC, 2,810cases and 43,751 controls), Clear cell (CCOC, 1,366 cases and 42,307 controls), Low malignant potential serous (LMSOC, 1,954 cases and 42,895 controls), and Low malignant potential mucinous (LMMOC, 1,149 cases and 42,090 controls). Association tests were adjusted for up to 19 genetic principal components in the data sources. Data from the consortia were extracted through the MR-Base platform [32]. Characteristics and detailed information on used data sources are displayed in Table S1 . All studies had been approved by a relevant ethical review board and participants had given informed consent.