For instance, pro-inflammatory cytokines, such as TNF-α and IL-1β, enhance IL-34 synthesis in fibroblasts, epithelial cells, intestinal lamina propria mononuclear cells (LPMC), periodontal ligament cells, osteosarcoma cells, and adipocytes, through NF-κB- and MAP kinase-dependent pathways [13,24,25,26]. This evidence concerns the gene IL34 and osteosarcoma.