Mouse plasma concentration of AMG 900 correlates with the degree of p-Histone H3 suppression in both COLO 205 tumor and mouse bone marrow tissues. Mice bearing established tumors were orally administered a single dose of vehicle alone or AMG 900 (as described in Figure 1). Mouse plasma was collected three hours after treatment (n = 10 per treatment group). Scatter plots were generated using the observed percentage of p-Histone H3 positive G2M cells for bone marrow (A) and COLO 205 tumor (B and C) and plasma concentration of AMG 900 (ng/mL) from individual mice. Treatment groups are indicated (○ vehicle, “green circle symbol” 3.75, “red circle symbol” 7.5, and ● 15 mg/kg). Regression analysis was used to assess linearity of p-Histone H3 response relationship across tissue sets (D) FCM bone marrow versus tumor, (E) FCM tumor versus LSC tumor. The correlation coefficient (R-squared value) and fitted line (red) are shown for each plot.