Although BRAF mutations were always found among nevus cells, cells that contained only wild-type BRAF predominated in nine of 13 nevi. When BRAF was sequenced from both alleles of four patients heterozygous for an adjacent polymorphism, both alleles harbored BRAF mutations.
"[P]olyclonality of BRAF mutations in the lesions of acquired melanocytic nevi suggests an alternative to the view that BRAF mutation is an initial event in melanocytic neoplasia," the authors write.
Source: Eurekalert
RAS