BRAF and hairy cell leukemia: Although these studies confirmed the occurrence of BRAF V(600)E as near universal in HCLc disease, interestingly and in marked contrast, in HCLv and in the unusual HCLc-IGHV4-34 cases, BRAF V(600)E was found to be invariably absent suggesting segregated pathways in the origins of these different forms of HCL disease [11,12].