CSF2 and spondyloarthropathy: In contrast, in inflamed joints during inflammatory arthritis, NK cells and macrophages are the primary GM-CSF producers (20, 29), while patients with spondyloarthritis exhibit increased GM-CSF-producing CD4+ and CD8+ lymphocytes in their joints, along with an expansion of GM-CSF-producing ILC3 in synovial tissues (30).