ERBB2 and malignant peripheral nerve sheath tumor: Premalignant Schwann cells carrying a point mutation in the Neu/Erbb2 gene diagnostic for the resulting MPNST emerge shortly after ENU exposure in both strains; however, mutant cells expand in trigeminal nerves of BDIX rats until full-blown tumors are present but disappear in BDIV nerve tissue about 3 months after neonatal ENU exposure (Kindler-Rohrborn et al. 2000).