A large number of such agents are now in clinical use, including epidermal growth factor receptor (EGFR) inhibitors in EGFR mutated non-small cell lung cancer (NSCLC) (4), anti-epidermal growth factor receptor 2 (HER2) agents in HER2-positive breast (5) and gastric cancer (6), B-rapidly accelerated fibro sarcoma (BRAF) inhibitors for the treatment of melanoma and other BRAF mutated tumors (7). The gene discussed is BRAF; the disease is gastric cancer.