Increased levels of the 4- and 9-gene signatures are associated with adverse OS. The patients in the validation set (ie, Netherlands-set I; n = 271) were dichotomized into 2 groups based on the median value of the 4-gene (4G signature; left panel) or the 9-gene (9G signature; right panel) signature, and then Kaplan-Meier curves were generated to depict outcomes. The P value was determined by log-rank test. | indicates censored.