CSF1 and Arthritis: Importantly, providing M-CSF/IL-4-treated PBMNCs significantly reduced the progression and the severity of the CFA-induced arthritis, compared to the joints on day 7 (p = 0.016, p < 0.05) and the PBS-treated joints on day 32 (p = 0.017, p < 0.05) (Fig. 6C).