In LCH, OC-like multinucleated giant cells are present not only in osseous but also in non-osseous lesions, such as skin and lymph node infiltrations, and can be activated by molecules such as RANKL and macrophage colony-stimulating factor (M-CSF) produced by both LCH cells and T cells. Here, TNFSF11 is linked to Langerhans cell histiocytosis.