An initial study indicated that the KAI1/CD82 gene exhibited the inhibition specifically towards the metastasis of prostate cancer (17); however, later studies have revealed that the inactivation of this gene occurs in a number of other malignant tumors, including thyroid (14), breast (18–20), endometrial (16), laryngeal (21), colon (22), gastric (7,23), gallbladder (24), liver (25), kidney (26), bladder (27) and prostate (28) cancer. This evidence concerns the gene CD82 and prostate cancer.