BRAF and hairy cell leukemia: In this case, the rapid reduction in WBC count with vemurafenib was promising, aligning with outcomes seen in other studies where BRAF inhibitors for HCL were used. The literature for the use of vemurafenib in the treatment of relapsed HCL shows good results; two multicenter studies were performed in Italy and the United States, showing that 91% of patients (n = 54) had an overall response while 35% of them had a complete response in the intention-to-treat analysis [14-16].