Irradiation and Atm loss were associated with changes in the expression of semaphorin genes specifically, semaphorin 6A (Sema6a) and semaphorin 3D (Sema3d) which have been implicated in the tumor cell proliferation and survival in glioma mouse models and in glioblastomas (22, 23). This evidence concerns the gene SEMA3D and central nervous system cancer.