The human tissue kallikrein(KLK)gene family consists of 15 highly conservative serine pro-teases,which is the largest uninterrupted cluster of protease genes in the human genome. Several members of the family are expected to be markers for tumor diagnosis and prognosis. Studies find that the expressions of KLK2-11 and KLK13-15 are abnormal,and the majority of KLKs have potential diagnostic and prognostic values.