The genetically linked SUZ12 gene has been identified as an important modifier of NF1 in MPNST.39 It is unknown if SUZ12 or any other gene that is commonly inactivated with NF1 in the setting of these large gene deletions plays a role in determining the number, size, or timing of onset of cNF. The gene discussed is NPHS1; the disease is malignant peripheral nerve sheath tumor.