SSX2 and Familial prostate cancer: In other studies humoral SSX2 immune responses were observed in 2 out of 74 colon cancer patient sera samples [99], 1 out of 100 prostate cancer patient sera [74], and antibody responses to SSX4, but not SSX2, have been identified in 2 out of 131 patients with gynecological cancers but not in healthy controls [100].