GPR155 and gastric cancer: Multivariate analysis identified low GPR155 mRNA expression levels in GC tissue as an independent predictive factor of synchronous hematogenous metastasis and metachronous hematogenous metastasis after curative gastrectomy (hazard ratio, 5.38; P = 0.001), together with CEA > 5 ng/ml, vessel invasion, and expansive growth (Table 3).