At this threshold, nine genes (ARL14EP, VEZT, CDC42, LINC00339, WNT4, GREB1, IL1A, FGD6, KDR) were genome-wide significant (Supplementary Table S6) in the gene-based analysis for the ‘IEC endometriosis’ GWAS, all of which have previously been reported for endometriosis (assessed using PhenoScanner v2 [49] (http://www.phenoscanner.medschl.cam.ac.uk, on 30 September 2019). This evidence concerns the gene IL1A and endometriosis.