BRAF V600 mutations are detected in ~ 7–15% of all cancers, although with different prevalence in different cancer types, including hairy cell leukemia (79–100%), melanoma (40–70%), papillary thyroid cancer (45%), ovarian cancer (35%), colorectal cancer (11%), cholangiocarcinoma (5–7%), multiple myeloma (4%) and non-small cell lung cancer (1–3%), but also in rare and very rare cancers, such as sarcomas, among others [44]. The gene discussed is BRAF; the disease is hairy cell leukemia.