KLK2 is a member of the grandular kallikrein protein family. Kallikreins are a subgroup of serine proteases that are clustered on chromosome 19. Members of this family are involved in a diverse array of biological functions. The protein is a highly active trypsin-like serine protease that selectively cleaves at arginine residues. KLK2 is primarily expressed in prostatic tissue and is responsible for cleaving pro-prostate-specific antigen into its enzymatically active form. This gene is highly expressed in prostate tumor cells and may be a prognostic maker for prostate cancer risk. Alternate splicing results in both coding and non-coding transcript variants. Recombinant human KLK2 protein, fused to His-tag at N-terminus, was expressed in E.coli.