Protein-protein interaction network of 138 genes. I2D version 1.72 was used to identify protein interactions for the 138 genes shown in the heatmap. The resulting network was visualized using NAViGaTOR 2.1.14 http://ophid.utoronto.ca/navigator. Color of nodes corresponds to Gene Ontology biological function, as described in the legend. Red-highlighted squares represent the four genes in the signature of OSCC recurrence.