Comparing the microglial staining in ipsilateral hemispheres of 0 Gy and 20 Gy-GBM143 with that of the ipsilateral hemispheres of two separate mice that were cranially irradiated with 20 Gy but not injected with any human-GBM PDX line (radiation controls): showed, negligible Iba1+ microglia staining in the brain slices of 20 Gy-IR alone, indicating, the observed microglial activation to be an effect of crosstalk between irradiation and tumor pathogenesis. The gene discussed is AIF1; the disease is neoplasm.