KLK6 and neoplasm: The kallikrein-related proteases are a family of secreted serine proteases, a number of which have been implicated in viral replication.4 KLK6, associated with neurological diseases like MS, Alzheimer's,5 and Parkinson's,6 and with the migration and invasion, and thereby metastasis, of tumor cells,7,8 has also recently been linked to the zoster (chickenpox) virus.9,10 Infected keratinocytes were found to overexpress KLK6 and MDM2, and their overexpression was directly linked to viral propagation.