Our proteomic analyses reveal that in comparison with the protein contents of U251/Res/Exo, the higher level of H2AX that sensitizes glioblastoma cells to apoptosis [37] and the lower levels of Rap1, F-actin and G proteins related with the enhanced drug sensitivity [38,39,40] and growth suppression of cancer cells [41] are found in U251/N/Exo. This evidence concerns the gene RAP1A and cancer.