To determine whether enhanced PRL signaling alone could induce adenomyosis, we generated PRL transgenic (PRL-TG) mice with increased circulating PRL levels (Fig. 5a) and evaluated their uteri at various time points via a grading system37 to measure the degree of myometrial invasion by endometrial tissue (Supplementary Fig. 6a). The gene discussed is PRL; the disease is adenomyosis.