Given we have previously detected a reduction in CD8+CD56+ T cells in patients with active LCH and highlighted a potential role for cytotoxic T cells in LCH pathogenesis (21) it would not be out of the question to consider that pro-inflammatory cytokine producing CD1a-autoreactive cells could have a potential role in the treatment of LCH. This evidence concerns the gene NCAM1 and Langerhans cell histiocytosis.