Immune response after low-dose radiotherapy in FL. (A) Postradiotherapy biopsies were stained with an anti-p53 antibody, revealed by a brown color, and a macrophage-specific CD68 antibody, revealed by a red color. Image was acquired with a ColorView (Mitsubishi, Tokyo, Japan) SIS CCD camera (400×, PlanApo, 40×/0.95) and DP Soft (Muenster, Germany) CVI 3.2 software. Results are representative of all macrophages found in the 5 patients tested. (B) Based on several genes overexpressed after radiation (in red), we propose a model for the molecular immune-reaction that follows low-dose radiotherapy.