SDC1 and prostate cancer: Although most of the 15 studies analyzing 18-551 prostate cancers have described associations of the altered CD138 expression with high Gleason grade, high Ki67 labeling index (Ki67LI), early recurrence, tumor-specific survival or elevated expression in hormone-refractory recurrences, and distant metastasis [15–28], there is still no consent on the suitability of CD138 as routine diagnostic marker.