The CD133−/CD133+ ratio was 2.5, namely the expression of TREX1 protein in the sorted CD133− cell subsets was 2.5 times of CD133+ cell subsets, and the difference was statistically significant (P < 0.05), as shown in (Fig. 12b), suggesting that the expression of TREX1 in CD133+ cell subset with the nature of osteosarcoma stem cells was significantly lower than that of CD133− cell subsets in non-osteosarcoma stem cells. The gene discussed is PROM1; the disease is osteosarcoma.