KLK10(kallikrein-related peptidase 10) also known as kallikrein 10, PRSSL1 or NES1, belongs to the kallikrein subfamily of serine proteases, which are involved in a variety of enzymatic processes. Its encoded protein is secreted and may play a role in suppression of tumorigenesis in breast and prostate cancers.KLK10 also contains 12 conserved cysteines in its protease domain that are expected to form 6 disulfide bonds, as in other serine proteases. RT-PCR detected variable levels of KLK10 expression in nearly all of the 35 adult and fetal tissues examined. The KLK10 gene contains 6 exons, the first of which is noncoding. By fluorescence in situ hybridization, Polikoff et al.(1997) mapped the PRSSL1 gene to 19q13.3. By genomic sequence analysis, Gan et al.(2000) mapped the KLK10 gene within the KLK gene cluster on chromosome 19q13. This cluster includes 13 KLK genes and 5 pseudogenes.