BRAF and Langerhans cell histiocytosis: In contrast, mutations in benign or low-grade tumors such as FGFR3 (seborrhoic keratosis and urothelial papillary tumors), BRAF (melanocytic nevi, Langerhans cell histiocytosis) and protein kinase C (benign fibrous histiocytoma) affect only single pathways and thus have far more restricted consequences for cellular homeostasis [72].