They provide genome-wide significant evidence for association with a splice variant (rs13394619) in the GREB1 (Growth Regulation By Estrogen In Breast Cancer 1) locus in women with European ancestry. Moreover, the 19 SNPs identified in endometriosis explain up to 5.19% of variance in endometriosis, suggesting that many more variants remain to be detected. This evidence concerns the gene GREB1 and endometriosis.