In this study we performed for the first time a direct comparison study of gene expression (CK-19, CK-8, CK-18, TWIST1, ALDH1, PSMA, AR-FL, AR-V7, AR-567 and PD-L1) and DNA methylation (GSTP1 and RASSF1A) markers in CTCs and paired plasma-derived exosomes and evaluated their prognostic significance in metastatic castration resistant prostate cancer. The gene discussed is AR; the disease is prostate cancer.