The low activation of NFκB detected in GICs suggests that NFκB may be dispensable for survival and proliferation of these tumor progenitor cells, which correlates with data showing that p65 immunoreactivity is abundant in the cytoplasm of the majority of cells within neurospheres derived from embryonic mouse brain, but only occasional weak nuclear localization (active state) is detected [9]. This evidence concerns the gene NFKB1 and neoplasm.