V600E is a mutation of the BRAF gene in which valine (V) is substituted by glutamic acid at amino acid 600. It is a driver mutation in a proportion of certain diagnoses, including melanoma, hairy cell leukemia, papillary thyroid carcinoma, colorectal cancer, non-small-cell lung cancer, Langerhans cell histiocytosis, Erdheim–Chester disease and ameloblastoma. From Wikipedia
