Mesenchymal carcinoma cells recruit immunosuppressive Tregs and M2 macrophages to the tumor microenvironment relative to their epithelial counterparts, which recruit cytotoxic CD8⁺ T cells instead. In carcinomas that are comprised of heterogeneous mixtures of both epithelial and mesenchymal cells, minority subpopulations of immunosuppressive mesenchymal carcinoma cells are able to protect the entire tumor, including its epithelial cells, from immune attack. Immunofluorescence analysis of mixed tumor sections revealed that mesenchymal (green) and epithelial (white) carcinoma cells segregate to distinct sectors of the tumor. F480⁺ macrophages (red) are interspersed only among the mesenchymal cells of the tumor, while only a few scattered macrophages are found at the periphery of epithelial sectors within the same tumor. For details, see article by Dongre and colleagues on page 3982.