Vemurafenib, a BRAF inhibitor, has shown promise in the treatment of patients with metastatic melanoma, non‐small cell lung cancer, papillary thyroid carcinoma, hairy cell leukemia, and Langerhans cell histiocytosis.31, 32, 33, 34, 35. This evidence concerns the gene BRAF and Langerhans cell histiocytosis.