NPAS2 and ovarian carcinoma: The goal of the current study was to examine variants in seven key circadian rhythm genes (BMAL1, CRY2, CSNK1E, NPAS2, PER3, REV1, TIMELESS) and two transcription factors (KLF10 and SENP3) activated by circadian rhythm gene expression as risk factors for epithelial ovarian cancer, histopathologic subtype, and invasiveness.