PTEN and meningioma: The CNV profiles showed a homozygous loss of CDKN2A/B, loss of PTEN, and/or NF2 genes in 0%, 0%, and 50% of grade 1 meningiomas; 0%, 42%, and 91% of grade 2 meningiomas; and 40%,100%, and 100% of grade 3 meningiomas, respectively (Table 2).