SPARC and neoplasm: To test whether SPARC produced endogenously by MDSC contributed to EMT, 106 MDSC isolated from the spleen of SN25ASP tumor-bearing WT or Sparc−/− mice, were injected, once a week for 4 consecutive weeks (Figure 2D), intra-tumorally into SN25ASP lesions grown in Sparc−/− mice.