KLK3 and neoplasm: In recent years, great progress has been made in the diagnosis or treatment of PCa with the identification of multiple diagnostic targets such as the main biomarker prostate-specific antigen (PSA), PCa antigen 3 (PCA3), the gene fusion test of TMPRSS2-ERG, circulating tumor cells, lncRNA biomarkers, and microRNA biomarkers [19–22].