A previous study also showed that upregulated secreted frizzled-related protein 1 (sFRP1) in the prostatic tumor stroma [37] could restore the activity of glycogen synthase kinase 3β (GSK3β), whereas inhibition of GSK3β abolishes the regulation of sFRP1 on SMAD3 signaling and the aggressive phenotype of gastric cancer [38]. This evidence concerns the gene SFRP1 and gastric cancer.