Mouse tumor model for neurofibromatosis type 1

Neurofibromatosis type 1 (NF1) is an autosomal dominant disorder characteri zed by increased incidence of benign and malignant tumors of neural crest o rigin. Mutations that activate the protooncogene ras, such as Loss of Nf1, cooperate with inactivating mutations at the p53 tumor suppressor gene duri ng malignant transformation, One hundred percent of mice harboring null Nf1 and p53 alleles in cis synergize to develop soft tissue sarcomas between 3 and 7 months of age. These sarcomas exhibit Loss of heterozygosity at both gene loci and express phenotypic traits characteristic of neural crest der ivatives and human NF1 malignancies.