SLC39A1 and prostate cancer: For this present study, the most important established relationships are: 1) the zinc levels are always markedly decreased in human prostate cancer as compared to the normal peripheral zone (where ~90% of malignancy arises); 2) the accumulation of zinc in the malignant cells exhibits cytotoxic/tumor suppressor effects; and 3) ZIP1 is the important functional zinc uptake transporter that is down regulated in the malignant cells in situ in prostate cancer; which protects the malignant cells from accumulation of cytotoxic levels of zinc.