To further define the relative contributions of microglia and myeloid cells recruited from the periphery, we isolated CD11b+/CD45low/Ly6C–/Ly6g– (corresponding to microglia) and CD11b+/CD45+/Ly6C+/Ly6g– (corresponding to infiltrating monocytes) cell populations from the brain hemispheres of tumor-bearing SE or EE mice (Figure 1b,c). The gene discussed is PTPRC; the disease is neoplasm.