Model refinement to 26 features improves predictive accuracy. A. Heatmap of signal intensities for the 26 genes in the refined model plotted by clinical sample. All clinical samples were included (KRAS WT, KRAS-mutant, and unconfirmed/NA) and are arranged according to PFS. Sixty and 120 day PFS are identified on the scale for approximate reference. KRAS-mutant samples (codon 12) are designated by red arrows. Genes which are more highly expressed in the 'sensitive' training data are marked with red on the probeset axis, while gene more highly expressed in the 'resistant' training data are marked in green. B. The confirmed KRAS-WT samples were plotted by predicted sensitivity. Closed circles and bars represent individual PFS and median PFS for the group, respectively. C. The Kaplan-Meier survival curve depicts PFS between the 'sensitive' (green) and 'resistant' (red) groups. The reported p-value is for the log-rank statistic.