H2AX and esophageal squamous cell carcinoma: We found that VAV2 overexpression significantly reduced both spontaneous and IR-induced DNA damages in ESCC cells as indicated by γ-H2AX levels analyzed by Western blotting and immunofluorescence (Fig. 3f–h); in contrast, knockout of VAV2 significantly increased γ-H2AX levels in cells with or without IR (Supplementary Fig. S3h–j).