A number of reports have shown that PRL is an immune-stimulating hormone that is capable of stimulating organ-specific inflammatory disease in humans. More recently, hyperprolactinemia has been associated with the active phase of the immune-complex-mediated autoimmune disease, systemic lupus erythematosus. The theory that PRL contributes substantially to disease activity was upheld in the NZB/W mouse model of spontaneous, hormone-sensitive lupus. Implanted pituitary glands resulted in hyperprolactinemia, accelerated proteinuria, high levels of circulating IgG, and premature death. Therapeutic studies with NZB/W mice, as well as anecdotal evidence from a small number of patients, have provided evidence that PRL suppressive therapy may be beneficial in selected cases of autoimmune disease.