Berres et al. [85] reported that patients with LCH-RO (+) carried the BRAF V600E mutation in circulating CD11c+ and CD14+ cellular fractions as well as in bone marrow CD34+ hematopoietic cell progenitors, whereas the mutation was restricted to lesional LCH cells in patients with LCH-RO (−). This evidence concerns the gene CD34 and Langerhans cell histiocytosis.