PRL signaling has been implicated in endometriosis, another condition characterized by the presence of ectopic endometrium.18 Thus, blockade of the PRL receptor (PRLR) has been shown to inhibit endometriosis in a mouse model and exhibits comparable efficacy to that of the antiestrogen drug Faslodex or the GnRH antagonist cetrorelix.19 In this study, we investigated the therapeutic potential of targeting the PRLR in adenomyosis by administering the monoclonal antibody HMI-115 to mice with intrauterine pituitary isograft-induced adenomyosis. Here, PRL is linked to endometriosis.