Most of the previous studies have mainly focused on the function of VAV2 as a guanine nucleotide exchange factor and suggested that it promotes tumor proliferation and invasion probably through the RAC1, CDC42 and RhoA pathways.31,35,36 However, in the present study, we have clearly demonstrated that VAV2 also participates in DNA NHEJ repair. This evidence concerns the gene RAC1 and neoplasm.