PDGFRA and glioma: PDGFRA gene amplification analysis revealed PDGFRA amplification in 21.1% (12 out of 57) of gliomas, a frequency similar to that described in previous studies (Fleming et al, 1992; Kumabe et al, 1992; Smith et al, 2000; Alonso et al, 2005; Arjona et al, 2005; Puputti et al, 2006; Beroukhim et al, 2007; McLendon et al, 2008).