KLK11(KALLIKREIN 11), also called PRSS20 or TLSP, is a protein that in humans is encoded by the KLK11 gene. KLK11 is a member of the kallikrein subfamily of serine proteases, which are involved in a variety of enzymatic processes. The KLK11 gene is mapped to 19q13.41. The KLK11 gene contains 6 exons, the first of which is noncoding. KLK11 shares 48% amino acid sequence identity with mouse neuropsin, 43% identity with both human trypsin-1 and human kallikrein, and 38% identity with the mouse nerve growth factor gamma subunit. Alternate splicing of the KLK11 gene results in two transcript variants encoding two different isoforms which are differentially expressed. Western blot analysis of recombinant KLK11 suggested that the protein is secreted and posttranslationally processed.