As it is believed that mucinous ovarian carcinomas may arise from pre-existing benign or borderline lesions (Powell et al, 1992; Scully et al, 1992, pp 139–144), upregulation of hK6 expression may be an early event of cancer development and hK6 may have potential as a novel biomarker for early detection of ovarian cancer. This evidence concerns the gene KLK6 and cancer.