||TO THE EDITOR: It has long been established clinically that patients with neurofibromatosis Type 1 (NF1) have an increased susceptibility to develop many central and peripheral tumors. The nature of the genetic alterations underlying NF1 have recently begun to be characterized. It has been demonstrated that the NF1 gene plays a critical role as a tumor suppressor and that patients with NF1 harbor mutations in the NF1 gene, which codes for neurofibromin, a functional negative regulator of signal transduction through Ras. Neurofibromatosis Type 1 is an autosomal-dominant cancer predisposition syndrome in which 15 to 20% of affected individuals develop astrocytomas that are most commonly pilocytic. The power of cell culture as a foundation of current molecular and cell biology is often not apparent to clinicians in the direct daily management of their patients. In the article by Kurimoto, et al. (Kurimoto M, Hirashima Y, Ogiichi T, et al: Establishment and characterization of a novel malignant astrocytoma cell line derived from a tumor removed in a patient with neurofibromatosis Type 1. J Neurosurg 94:301-308, February, 2001), the authors have established in tissue culture an immortalized cell line (TM-31) from a high-grade glioma in a patient with NF1. Although malignant glioma lines are established routinely in most laboratories in which intracranial tumors are studied, to date there has been no available established glioma line from a patient with NF1. This cell line offers a unique opportunity to study the genetic alterations, growth, and invasive characteristics in vitro.