We examined the expression level of a series of AR-regulated genes including KLK2, kallikrein-related peptidase 2 gene; KLK3, kallikrein-related peptidase 3 gene (or PSA, a marker for PCa screening); TMPRSS2, transmembrane protease serine 2 gene; FKBP5, peptidyl-prolyl cis–trans isomerase (or FK506 binding protein 5) gene; PLZF, promyelocytic leukemia zinc finger protein, which is a putative tumor suppressor gene in PCa; and cdc20, cell division cycle 20 homolog. The gene discussed is KLK2; the disease is neoplasm.