ENPP1 knockdown reduce the stem cell phenotype of lung tumors. A, B. Immunoblot analysis of the cancer stem cell makers of ABCG2, SOX2, NANOG in HCC827-shNS, HCC827-shENPP1 and A549-shNS, A549-shENPP1 cell lines. C-F. The expression of CD44 analysis by flow cytometry as the protocol indicated. *, P<0.05; **, P<0.01; ***, P<0.001; ****, P<0.0001. G. ENPP1 knockdown reduces tumorigenesis in vivo. HCC827-shNS and HCC827shENPP1-2# cells were inoculated subcutaneously on nude mice, after 2 weeks, representative images of tumors and the tumor size was measured at indicated time points.