SPARC and neoplasm: Large tumors developed in animals injected with only KCNR cells (mean tumor size 693±329 g) or KCNR mixed with shSHEP cells with down-regulated SPARC (mean tumor size 662±470 g), whereas tumors in mice injected with KCNR mixed with vcSHEP cells were significantly smaller (mean tumor size 366±236 g, p=0.03) (Figure 2).