STAT3 and cancer: Cloning formation assay showed that stattic could increase the radiosensitivity of HCC cells, as shown in Table 1, the value of D0, Dq, and SF2 was decreased in stattic group, and the SER of D0 is 1.56, 1.60, and 1.69 in Hep G2, BEL-7402, and SMMC7721, respectively, which indicates that STAT3 may be a new target for cancer radioresistance.