CSF2 and rheumatoid arthritis: Immune cells (i.e., neutrophils, monocytes (Mo), macrophages (Mφ), dendritic cells (DCs), T and B cells) are involved in the balance between the processes of bone formation and bone resorption linked to various bone diseases, such as rheumatoid arthritis (RA), periodontitis, delayed bone regeneration, and other bone abnormalities diseases.4,5 Cytokine production (i.e., RANKL, GM-CSF, TGF-β) during immune responses could profoundly affect bone homeostasis by altering the balance between bone-forming osteoblasts (OBs) and bone-resorbing osteoclasts (OCs).