FJX1 and endometriosis: FJX1 protein levels in the endometrium of women without endometriosis do not fluctuate during the menstrual cycle, however, during normal endometrial secretion, FJX1 levels in women with endometriosis were considerably greater than in those without endometriosis, implying that elevated FJX1 protein levels may play a role in endometriosis etiology (Chang et al., 2018).