In addition, the STAT1 levels were positively correlated with the levels of VAV2 in ten ESCC cell lines (r = 0.734, P = 0.0156; Supplementary Fig. S5g) and were substantially higher in IR-induced radioresistant KYSE150 and KYSE450 cells having high VAV2 expression compared with that in the parental cells having lower VAV2 expression and sensitive to IR (Fig. 5d). Here, STAT1 is linked to esophageal squamous cell carcinoma.