Following a literature review and subsequent preclinical evaluation of candidate genes we identified six genes (kallikrein 2, 3, and 4 (KLK2, KLK3, and KLK4), prostate-specific membrane antigen (PSMA), transmembrane serine protease 2 (TMPRSS2), and transient receptor potential cation channel subfamily M member 8 (TRPM8)) suitable for molecular LN analysis with high expression in PC and low expression in peripheral blood mononuclear cells (PBMCs), which can be used as a model for detection of disseminated tumor cells in LNs [22]. The gene discussed is KLK2; the disease is neoplasm.