All strains had significantly increased PRL levels in sera in response to metoclopramide (hyperprolactinemia), while only MRL/lpr mice showed a significant increase after PBS treatment, which was likely age-related (15 weeks at the end of treatment); however, the PRL increase in the PBS group was lower than in the group treated with metoclopramide (Table 1). Here, PRL is linked to hyperprolactinemia.