NOS2 and neoplasm: At 7 dpi, >60% of SDF-1+F4/80+ cells appeared to be CD206+ M2 macrophages in WT, but not EC-p53KO tumours, whereas more iNOS+ M1 macrophages were found in EC-p53KO than in WT tumours (Fig. 6e, Supplementary Fig. 13b).