PDGFB and benign meningioma: To determine if Nf2 loss alone or in combination with Cdkn2ab loss could promote progression of PDGF-B induced benign meningiomas, we generated cohorts of PGDStv-a;RCAS-PDGF-B;AdCre;Nf2flox2/flox2 and PGDStv-a;RCAS-PDGF-B;AdCre;Nf2flox2/flox2; Cdkn2ab−/− mice.