The first attempt to induce the loss of Cdkn2a, via adding nullizygosity for p16Ink4a in adCre; Nf2flox2/flox2 mice, resulted in an increased rate of meningiomas development and meningothelial proliferation, but it did not modify the tumor grade (Table 3) [67]. The gene discussed is CDKN2A; the disease is meningioma.