The BRAF V600E mutation is found across cancer types including >97% of hairy cell leukemias, 40–67% of melanomas, 36–69% of papillary thyroid tumors, 15–20% of low-grade pediatric tumors, and 5–17% of colorectal cancers [12,13,14,15,16]. The gene discussed is BRAF; the disease is hairy cell leukemia.