PROM1 and neoplasm: The results showed that 10,000 CD133+ SMMC-7721 cells were sufficient to induce tumor formation in 5/5 (100%) and intrahepatic metastasis in 2/5 (40%) NOD/SCID mice after 3 months, whereas an equivalent number of CD133− cells only induced tumor formation in 3/5 (60%) mice and did not induce tumor metastasis (Figure 2A, B, C).