MRC1 and breast cancer: Additional immunofluorescence staining was performed to assess the association of the iron(III)+ cells with other macrophage subsets at cellular resolution, confirming the immunohistochemical determination of the co-localization with CD68, and further revealing that these macrophages also express both pro-inflammatory (AIF1+, allograft inflammatory factor 1) and anti-inflammatory (CD206+, mannose receptor) markers in the mammary tumors, livers, and spleens (Fig 2c).