The average concentrations of SPON2 in the plasma of healthy donors, CRC patients, CRC patients after surgery, gastric cancer (GC) patients, prostate cancer patients and benign prostatic hyperplasia patients were 8.8, 21.6, 12.7, 13.4, 7.6 and 4.5 ng/mL, respectively. Here, SPON2 is linked to gastric cancer.