GM-CSFRα neutralization using the mAb, CAM-3003, was shown to be as effective as anti-GM-CSF and anti-TNF mAbs in suppressing manifestations of murine collagen-induced arthritis, including the degree of synovial inflammation [11, 33, 36, 37]; the clinical benefit is also similar in RA trials using GM-CSF receptor or GM-CSF neutralizing mAbs [2, 38]. This evidence concerns the gene CSF2 and inflammatory response.