To further investigate the biological role of WFDC21P in GC cells, lentivirus vectors with stable overexpression and knockdown of WFDC21P were conducted and successfully transfected into MKN-45 and HGC-27 cells (the two cell lines with the lowest expression and the highest expression of WFDC21P, respectively). The gene discussed is WFDC21P; the disease is gastric cancer.