Based on the classification of nervous system tumors previously reported, in the following paragraphs we described the role of TG2 in the context of pathogenesis of these tumors, in particular its involvement in radio- and chemoresistance mechanisms in GBMs and meningiomas, tumor inflammation in medulloblastomas, and differentiation in NBLs and GBMs. The gene discussed is TGM2; the disease is neoplasm.