In one prostate cancer diagnosis study, it showed that levels of CLDN3 in exosome were higher in patients with Gleason≥8 tumors than that patients with benign prostatic hyperplasia (p = 0.012) and Gleason 6–7 tumors (p = 0.029), and higher levels of annexin (CD62, CD81), heat shock proteins (Hsp70, Hsp90) and many signal molecules (TGF-β2, TNF-α, IL-6 TSG101) were expressed in prostate cancer cell-derived exosome cultured in hypoxic condition than that of normally cultured cells. Here, CD81 is linked to Familial prostate cancer.