DKK1 increased tumorigensis in the transgenic mouse model. A. DNA mixtures were injected into the lateral tail veins of 4-week-old mice and the livers were harvested at 9 weeks. B. Forced expression of DKK1 with HRAS in transgenic mouse liver resulted in the formation of more tumors (n=5), compared to the controls. C, D. H&E and IHC staining for HRAS, Ki-67, p-Akt and p-VEGFR2 on serial paraffin sections of HI_Luc2A and HI_DKK1 tumors (magnification, 200 ×). E. Lysates of HI_Luc2A and HI_DKK1 tumors were probed with the indicated antibodies. GAPDH was used as a loading control.