JAK2 and endometriosis: To determine if IL6ST exerts regulatory influence on progression of endometriosis through JAK2/STAT3 signaling pathway, cells transfected with IL6ST overexpression vector exhibited strikingly elevated levels of p-JAK2/JAK2, p-STAT3/STAT3, HIF-1α, and VEGF proteins in contrast to cells transfected with the empty vector (Fig 3A and 3B).