STC2 and cancer: Other secreted protein markers, listed in Table 2, that have been demonstrated as indicators of cancer are CTHRC1 (metastatic colon cancer) [68], ESM1 (metastatic colon cancer) [69], ADAM12 (advanced stage prostate cancer) [70], PDGFB (oral squamous cell carcinoma) [71], and STC2 (laryngeal squamous cell carcinoma) [72,73].