Receiver operating characteristic (ROC) analysis showed that both serum exosomal HOXD-AS1 and PSA could discriminate between patients with metastasis and localized controls, and the diagnostic accuracy was not significantly different for diagnosing distant metastasis in PCa (0.797, 0.722–0.872; 0.878, 0.802–0.955, respectively, P = 0.14, Fig. 6H, Fig. S9). The gene discussed is KLK3; the disease is posterior cortical atrophy.