In the meta-analysis, significant differences in serum levels of endostatin were observed between GC patients and control subjects, showing increased level of endostatin in GC patients according to the random effects pooled SMD in the 11 studies (SMD = 1.418, 95% CI = 1.079~1.757, P < 0.001) (Figure 2). Here, COL18A1 is linked to gastric cancer.