In contrast, a reduction of KiSS-1 expression in brain metastases has observed, thus suggesting that a loss of KiSS-1 may influence the formation of distant metastases; we speculate that further investigations on KiSS-1 expression levels in metastastic lesions and primary tumors in breast cancer patients could confirm the antimetastatic role of Kp (21). Here, KISS1 is linked to breast carcinoma.