CDKN2A and glioblastoma: Furthermore, AnnexinV-staining showed a five-fold increase in the number of apoptotic cells after repression of miR-21 by LNA-miR-21 both in an p16Ink4a/p19Arf double knockout mouse glioma cell culture as well as in the human glioblastoma cell line LN18 (Figure7A).