Somatic mutations in BRAF have been found in up to 10% of all NSCLC, more common in adenocarcinomas. D594 is a highly conserved residue within the kinase domain of BRAF and mutation of this residue appears to result in kinase inactivation. In vitro study has shown that kinase-dead BRAF forms a constitutive complex with CRAF in the presence of activated RAS leading to MEK and ERK signaling. The predictive and prognostic significance of this mutation needs further study. Clinical correlation is recommended.