SPP1 and neoplasm: To further confirm these finding, we established subcutaneous implantation nude mice models using RBE cells with OPN overexpression but β-Catenin knockdown, and found that up-regulation of OPN significantly enhanced tumor growth (Fig. 5d and Supplementary Figure 5C), metastases to the mesenteric lymph nodes (Fig. 5e,f), lung (Fig. 5f) and liver (Supplementary Figure 5D).