Furthermore, this study demonstrated that overexpression of mir-21 has a negative effect on the expression of CCL28, NR3C2, and SYNPO2 and plays a significant role in the progression of gastric cancer, whereas suppression of mir-21 with anti-mir-21 has an effect on the expression of CCL28, NR3C2, and SYNPO2. The gene discussed is SYNPO2; the disease is gastric cancer.