SMN1 and melanoma: Therefore, we dual-stained BRAFV600E primary melanoma tissue samples with MART1 and either the fibroblast marker smooth muscle actin (SMA) or the monocyte-macrophage marker CD68, and isolated cell compartments consisting of 20–50, clearly MART1− but either SMA+ or CD68+ cells with fibroblast and macrophage morphology, respectively, using laser-capture microdissection (Figure 2a,b).