A 66-year-old light former smoker (<5 packs per year smoking history) was diagnosed in April 2002 with stage IV lung adenocarcinoma....patient identified a somatic mutation, ARAF S214C, present in the cancer genome and expressed at high levels....our genomic and functional results suggest the transforming ARAF codon 214 substitution as the most likely driver of this patient’s tumor and determinant of its sorafenib response.