Five additional new loci significantly associated with the risk of endometriosis (p < 5 × 10−8) of genes involved in sexual steroid hormone pathways (FN1, CCDC170, ESR1, SYNE1 and FSHB) were identified, for a total of 16 genomic regions associated with endometriosis risk in one or more populations [27]. Here, CCDC170 is linked to endometriosis.