B-raf proto-oncogene belongs to a large group of serine/threonine kinases of RAF family, involved in the transduction of mitogenic signals from the cell membrane to the nucleus. This protein kinase is frequently mutated in thyroid cancer and human melanomas, less frequently in other types of malignant tissues, including colorectal cancers, lung cancers and gliomas. Ninety percent of B-raf mutations are represented by B-raf V600-E mutation, presented by up to 500-fold increased activation in MEK/ERK signaling in tumor cells.