GRPR and breast carcinoma: In our study, NMBR was overexpressed in endocrine-responding tumors, consistent with the results of recent studies on GRPR, the most important paralog of NMBR. High GRPR expression has been recently associated with a lower risk of distant metastases in breast cancer and prolonged progression-free survival after initiation of first-line tamoxifen therapy [23, 24].