hCD68-GFP labels resident and inflammatory macrophages. Mice expressing GFP under control of the human CD68 promoter carry resident macrophages with high levels of GFP in the spleen, liver, lungs, brain, and peritoneum. In addition, circulating monocytes are GFP⁺ and retain high levels of GFP even after transmigration and differentiation toward macrophages. Panels from Figure 2 and Figure 5 in the article by Iqbal et al beginning on page e33. Professional illustration by Luk Cox, Somersault1824.