ROC curve showed that the status of GC was able to be predicted by using expression levels of COL1A1 and COL4A1 (Fig. 5, area under curve (AUC) = 0.841, P < 0.001; AUC = 0.775, P < 0.001, respectively) but not CDK6 expression (Fig. 5, AUC = 0.575, P = 0.100). This evidence concerns the gene COL1A1 and gastric cancer.