Functional studies aimed at evaluating the effect of M-CSF-1 and/or IL-34 neutralization in murine models of colitis showed that pre-treatment of mice with both anti-M-CSF1 and anti-IL-34 one day prior to DSS challenge reduced the number of intestinal macrophages, the expression of inflammatory cytokines and limited damage as compared to mice treated with control antibody. The gene discussed is IL34; the disease is colitis.