PTEN and glioma: Furthermore, McEllin and associates utilized a compound Pten-Ink4a/Arf double knockout line [29], which complicates these conclusions as this same group previously published that de novo DNA damage induced in Ink4a/Arf single knock-out mice promotes DNA double-strand break-mediated high-grade gliomas [81], which may suggest synergism between PTEN and INK4a/ARF in regulating RAD51 paralog-mediated expression and DNA repair.