Using mice that lack DUSP2, a nuclear phosphatase shown to promote the production of pro-inflammatory cytokines, nitric oxide and prostaglandin E2 by activated macrophages and mast cells [18], we assessed whether DUSP2 represented a therapeutic target by which MAPK-dependent inflammatory gene expression associated with obesity could be suppressed. This evidence concerns the gene DUSP2 and obesity due to melanocortin 4 receptor deficiency.