CD68, CD163, and matrix metalloproteinase 9 (MMP-9) co-localization in breast tumor microenvironment predicts survival differently in ER-positive and -negative cancers.

Macrophage activity markers correlate with survival differently in ER+ and ER- cancers. The association between high co-expression and co-localization of MMP-9/CD163/CD68 and poor survival in ER+ cancers suggests that these cancers may be candidates for macrophage-targeted therapies.