BRAF alterations occur in approximately 2%-5% of nonsquamous non–small-cell lung cancer (NSCLC) and can be classified into three functional classes on the basis of their effect on the BRAF kinase domain.1,2 Class 1, represented by BRAFV600 mutations, strongly activates the BRAF kinase domain as a monomer, driving the constitutive activation of the downstream MAPK pathway independently of RAS activation. Here, BRAF is linked to lung cancer.