Indeed, LOH involving large parts of 22q is a key mutational step to mediate the concurrent loss of NF2, SMARCB1 and eventually also LZTR1. It should be noted that 83% of all NF2-associated schwannomas exhibit a mosaic SMARCB1 protein expression pattern resulting from intermixed tumour cells with and without SMARCB1 expression (Patil et al. 2008). This evidence concerns the gene LZTR1 and schwannoma.