Sardana et al analyzed the CM proteomics from the PC3, LNCaP, and 22Rv1 prostate cancer cell lines by two-dimensional chromatography and tandem mass spectrometry, obtained four candidate biomarkers including spondin-2, and discovered that its expression level in sera showed a significant difference between patients with or without prostate cancer [22]. This evidence concerns the gene SPON2 and Familial prostate cancer.