DKK1 and neoplasm: Tumor size was significantly reduced in DKK1 Tg mice versus wild-type controls (2,590 ± 463 vs. 3,368 ± 856 mm3, respectively; Fig. 2a, left panel; p < 0.001), which correlated to increased survival in DKK1 Tg mice (Fig. 2a, right panel; p < 0.001).