TP53BP1 and neoplasm: IHC staining showed that compared with the sh-NC group, HOTAIR silencing or irradiation treatment alone did not show an observable effect on γH2AX and 53BP1 staining in the tumor tissues; whereas the joint application of HOTAIR silencing and irradiation strongly increased the staining levels of γH2AX and 53BP1 (Fig. 4D).