In RA-associated interstitial lung disease (RA-ILD), Sendo et al. (38) found that CD11b+Ly6Chigh cells (M-MDSCs) isolated from the lungs could develop the CD11b+Gr-1dim phenotype when cultured with GM-CSF and IL-4-producing cells and the CD11b+Gr-1dim cells could inhibit T cell proliferation. The gene discussed is CSF2; the disease is rheumatoid arthritis.