SFRP4 and gastric cancer: The disease-free survival (DFS) and overall survival (OS) curves showed that GC patients with high transcriptional levels of SFRP1 (p = 0.014), SFRP2 (p = 0.039), and SFRP5 (p = 0.038) were significantly associated with short DFS, but patients with high transcriptional levels of SFRP3 or SFRP4 did not show such association (Figure 3A).