Fig. 6

Macrophage staining. Macrophage abundance in low mammographic density (LMD) (a, c) and high mammographic density (HMD) (b, d) paired samples (n = 15) stained with pan-macrophage marker CD68 (A, B) and the C-type lectin receptor macrophage mannose receptor 1 (c, d). Epithelial cell–associated (arrows) and stromal cell–associated (arrowheads) macrophages were quantified per square millimetre of tissue in three randomly selected glandular and stromal areas within each tissue sample, and abundance was compared between LMD and HMD paired samples using the nonparametric Wilcoxon test for epithelium and the paired t test for stroma (data passed the D’Agostino-Pearson omnibus normality test) (*P < 0.05). Percentage changes in abundance of epithelial and stromal cell–associated CD68 (e) and CD206 (f) in HMD tissue compared with the LMD paired sample are shown