Effect of Testosterone Administration on Serum and Urine Kallikrein Concentrations in Female-To-Male Transsexuals (Endocrinology and Metabolism‪)‬

Human tissue kallikreins (hKs) (6) comprise a subgroup of 15 homologous secreted serine proteases encoded by a tightly clustered multigene family on the long arm of chromosome 19 (KLK1-KLK15)'. hKs are involved in a wide range of physiological functions and are primarily expressed within the glandular epithelia in many tissues, including the skin, the central and peripheral nervous system, and also in endocrine glands and hormone-dependent tissues such as breast, endometrium, and prostate (1). In addition to prostate-specific antigen (PSA, hK3), which has important applications as a marker for prostate cancer diagnosis and follow-up, and hK2, an emerging prostate cancer biomarker, many other members of the kallikrein family are also implicated in endocrine-dependent malignancies. All kallikreins studied to date are known to be up- or down-regulated at the mRNA and/or protein level in breast, prostate, ovarian, and testicular cancers (2).