Kallikreins are a subgroup of serine proteases having diverse physiological functions. Growing evidence suggests that many kallikreins are implicated in carcinogenesis and some have potential as novel cancer and other disease biomarkers. KLK15 is one of the fifteen kallikrein subfamily members located in a cluster on chromosome 19. In prostate cancer, it has increased expression, which indicates its possible use as a diagnostic or prognostic marker for prostate cancer. KLK15 contains multiple polyadenylation sites and alternative splicing results in multiple transcript variants encoding distinct isoforms. Recombinant human KLK15 protein, fused to His-tag at N-terminus, was expressed in E.coli .