We found MCM3 overexpression increased the radioresistance, previous studies show cancer stem cells are the main reason for tumor relapse, metastasis, radiotherapy and chemotherapy resistance generation [38], Many cancer types have been reported to exist cancer stem cells, including HCC, EpCAM, CD13, CD133, CD90, CD24 and CD44 have used for the markers for HCC stem cells [39, 40]. This evidence concerns the gene CD44 and hepatocellular carcinoma.