MIF and myositis disease: Another study suggested the role of macrophages for development of myositis associated with RRV [71] by the action of macrophage migration inhibitory factor (MIF), a factor indicating the activation of macrophages, as shown in a mouse model in which a higher level of MIF was correlated with higher inflammation (by modulation of pro-inflammatory cytokines) and severity of disease (more cell infiltrates and more muscle disruption).