Reid BM, et al. - Via this genome-wide association study, researchers explored common (>1%) copy number variation (CNV) regions (CNVRs) in association with epithelial ovarian cancer (EOC) and high-grade serous (HGSOC) risk. They genotyped nearly 3,500 cases and controls with the Illumina 610k and HumanOmni2.5M arrays and quantified CNV in the DNA of these. They performed in silico analyses of tumor-gene expression by using The Cancer Genome Atlas (TCGA). EOC risk was linked to three: two large (~100kb) regions within the 610k set and one small (<5kb) region with the higher resolution 2.5M data. Five CNVRs were associated with HGSOC, including two reduced-risk deletions: one at 1p36.33 showed correlation with lower CDKIIA expression in TCGA tumors, and another at 8p21.2 that was present somatically where it correlated with lower GNRH1 expression. Findings suggested no great contribution of CNV to EOC susceptibility, but there was a possibility that a number of low-to-common frequency variants could impact the risk of EOC and tumor gene expression.