One of the first studies documenting the over-expression of IL-34 in neoplastic diseases was provided by Baud’huin and colleagues, who reported elevated levels of the cytokine in giant cell tumor (a benign bone tumor) and documented the ability of IL-34 to stimulate osteoclastogenesis via a CSF1-independent CSF1R activation [42]. The gene discussed is IL34; the disease is bone benign neoplasm.