There is a finding that Th17 cells are existed in endometriosis and IL-17A, as a key effector molecule of Th17 cells, it can play a vital role in promoting the progression of endometriosis by inducing the secretion of pro-inflammatory factor IL-8 together with the proliferation of endometrial stromal cell and the expression of COX2 (64). The gene discussed is IL17A; the disease is endometriosis.