Figure 1. Schematic diagram for a multi-step strategy to identify gene signature for prognosis in gastric cancer.

Robust likelihood-based survival model with 1000 iterations were constructed for selection of stable feature. After that, genes were defined as positive-impacting factors with expression higher than median (genes with positive) and negative-impacting factors with expression lower than median (genes with negative). This process is basing on the expressing patterns in the clustering analysis to go on with survival analysis.