KLK3 and benign prostatic hyperplasia: In a prospective study using nanoparticle tracking analysis, immunocapture-based ELISA, and nanoscale flow cytometry, circulating exosomes expressing both CD81 and PSA were found to be promising tools for differentiating PCa patients from healthy individuals or benign prostatic hyperplasia patients, with an impressive specificity and sensitivity rate of nearly 100% [54].