Fig. 4.

Most common pathways of genetic alterations involved in the progression of diffuse astrocytomas [according to the World Health Organization (WHO) classification]. The diagram shows that primary glioblastoma manifests with no clinical or pathological evidence of malignant lesions and that a previous secondary glioblastoma develops from a low-grade astrocytoma or anaplastic astrocytoma. LOH 10q Loss of heterozygosity on chromosome 10q, EGFR epidermal growth factor receptor, TP53, PTEN, p16INKa tumor suppressor genes. Adapted from Ohgaki and Kleihues (2007)