In a model of M. leprae granuloma, Wang et al. suggested that macrophages differentiated from peripheral blood monocytes using M-CSF, rather than granulocyte/monocyte (GM)-CSF, had a higher production of IL-10 in response to M. leprae infection (Wang et al., 2013), which could prove of interest bearing in mind the previous observations. The gene discussed is IL10; the disease is Granuloma.