(B) Fluorescence microscopy of tumor sections from Foxp3-eGFP WT (n = 4) and Cd300a−/− (n = 7) mice, stained with an anti-GFP monoclonal antibody (green) and the DNA-binding dye 4′,6-diamidino-2-phenylindole (DAPI; left). Here, FOXP3 is linked to neoplasm.