FN1 and endometriosis: The most striking observation of an association that became close to genome-wide significance when limiting cases to the much smaller subset with known Stage III/IV disease (n = 2859) is rs1250248 in FN1, which had an association OR = 1.11 (95% CI: 1.04–1.18, P = 1.1 × 10−4) with all endometriosis, and an OR of 1.27 (95% CI: 1.16–1.38), P = 8.0 × 10−8) with Stage III/IV disease.