KLK3 and pachyonychia congenita: Multi-parameter FC was tested on cryopreserved peripheral blood mononuclear cells (PBMC) collected from men with PC at different stages and variably treated, including: group 1, non-castrate, non-metastatic, PSA-recurrent cases; group 2, castration-resistant, non-metastatic PSA-recurrent tumors; and group 3, metastatic, castration-resistant PCs (mCRPCs).