They are CD68 -postive monocytic cell lineage composed of predominantly macrophages recruited in response to macrophage colony-stimulating factor 1 (CSF1).[17] Understanding of various molecular mechanisms responsible for osteoclast activation and osteoclast-like cell formation in certain neoplasms should lead to novel therapeutic approaches.[17, 18] However, due to the rarity of ORUCUB, the mechanism of multinucleated giant cell formation has not been investigated. The gene discussed is CSF1; the disease is neoplasm.