EPAS1 and Infertility: Mechanistic studies of endometriosis associated with EPAS1 are lacking, but it is certain that EPAS1, as a key transcription factor in cellular response to hypoxia, is closely associated with inflammatory response and angiogenesis under hypoxic conditions, and more importantly, EPAS1 expressed in the endometrial stroma has been associated with invasion of trophoblast cells during embryo implantation, and mice knocked out of EPAS1 expression were infertile due to infertility due to failure of implantation52,53.