Moreover, we chose the 1321N1 cell line with mutated cellular tumor antigen p53 (mut p53 R213Q) as a model, because the p53 gene is mutated in approximately 40% of astrocytic tumours and dissection of the molecular pathogenesis of astrocytic tumors has identified defects in the p53 pathway as one of the most common molecular alterations observed in human astrocytoma involved in both the early transforming events and progression from low-grade to high-grade neoplasms. The gene discussed is TP53; the disease is astrocytoma (excluding glioblastoma).