CSF2 and rheumatoid arthritis: For example, in patients with rheumatoid arthritis, fibroblasts have been shown to respond to and secrete a combination of TNF-alpha, IL-1, IL-6, and granulocyte-macrophage colony-stimulating factor (GM-CSF), while expressing a multitude of toll-like receptors in order to amplify T-Cell response to TLR activation (Ospelt, 2017).