Although it was reported that exposure of Blau syndrome patients’ peripheral blood monocytes to IL-4 plus M-CSF caused their morphologic change into fibroblastic/dendritic cells with Langhans-type MGCs, neither fibroblastic/dendritic change nor MGC formation was induced in our THP-1 variants by this method [13]. The gene discussed is CSF1; the disease is Blau syndrome.