Similar to schwannomatosis patients, loss of both Smarcb1 and Nf2 does not increase the malignancy of mGFAP-Cre;Smarcb1flox/flox;Nf2flox/flox tumors compared to mGFAP-Cre;Nf2flox/flox tumors with single Nf2 loss. This evidence concerns the gene SMARCB1 and schwannomatosis.