It is consistent with the previous findings that malignant gliomas (anaplastic astrocytomas and the most malignant type, glioblastoma multiforme) overexpress the ligands PDGF-A and -B compared to low-grade gliomas or normal tissues (Maxwell et al, 1990; Hermanson et al, 1992; Guha et al, 1995). This evidence concerns the gene PDGFA and glioblastoma.