Nevertheless, these four types share a common pathophysiology related to the clonal accumulation of mononuclear phagocytes associated with histiocytosis exhibit mutations in genes such as CSF1R, ALK, RET, NTRK, RAS, RAF, or MAP2K, which connect the binding of myeloid cell-specific growth factor receptors to the activation of the ERK signaling pathway (10). This evidence concerns the gene ALK and Histiocytosis.