Interestingly, proliferating cells in LCH granulomas are mostly endothelial cells, fibroblasts, and T cells (10, 11), as CD1a+ LCH-DCs do not proliferate, albeit they display an extended lifespan due to the activation of survival pathways and inhibition of apoptosis (12, 13). This evidence concerns the gene CD1A and Langerhans cell histiocytosis.