All the Nras G12D/G12D mice die with a severe myeloproliferative disease. After pI-pC injections, control and Nras G12D/G12D mice were kept for an extended period of time until Nras G12D/G12D mice reached a moribund stage. (A) Kaplan-Meier comparative survival analysis of control and Nras G12D/G12D mice. Cumulative survival was plotted against days after the first pI-pC injection. (B) Splenomegaly in Nras G12D/G12D mice. Results are presented as averages of spleen weights + SDs. (C) Representative histologic H&E sections from spleen show an extensive infiltration of myelomonocytic cells and extramedullary hematopoiesis in Nras G12D/G12D mice. (D) Complete blood count was performed on peripheral blood samples drawn from control and Nras G12D/G12D mice. *P < .05. (E-F) Quantitative analysis of myeloid progenitor (MP) compartment in bone marrow (E) or spleen (F) of control and moribund Nras G12D/G12D mice as described in Figure 3. Results are presented as averages + SDs. *P < .05.