TP53 and astrocytoma (excluding glioblastoma): Another region of interest is on 17p13.3, telomeric to the TP53 locus in several types of tumours, where the presence of new tumour suppressor genes is indicated in hepatocellular carcinoma, malignant astrocytoma, paediatric primitive neuroectodermal tumours, breast cancer, high grades of astrocytic tumours, and ovarian cancer (Biegel et al, 1992; Saxena et al, 1992; Nishida et al, 1993; Isomura et al, 1994; Phillips et al, 1996; Chattopadhyay et al, 1997; Haataja et al, 1997).