BMP2 and plexiform neurofibroma: Our evaluation of expression profiling data of tissue samples from NF1 patients by an independent group [33] showed that BMP2 is significantly up-regulated in both plexiform neurofibromas and MPNSTs with considerably higher levels in MPNSTs [24], suggesting that BMP2 may be one of the key players in the transformation of benign neurofibromas to a malignant phenotype.