Previous studies, including in silico analyses, have shown that the expression level of KLK10 is decreased in majority of breast cancer cell lines, whereas transfection of the KLK10 gene into KLK10-negative breast cancer cells can suppress tumour formation in nude mice8, thereby suggesting that this gene may function as a novel putative tumour suppressor13, 14. Here, KLK10 is linked to breast carcinoma.