Specifically, neurofibromas in NF1 range from pNF (deep lesions originating in nerve) to subcutaneous neurofibromas (lesions in the hypodermis of skin such that skin can be moved over the tumor) to cNF (currently defined as tumors limited to the skin, epidermis, and dermis, such that they move with the skin).18, –, 20 A key limitation for advancing research for these tumors is the great variability in the definitions applied to NF1-associated peripheral lesions preventing efficient therapeutic development in these tumors. This evidence concerns the gene NPHS1 and neoplasm.