Relative proportions of cluster 2 were dramatically altered by breast cancer, increasing from being almost non-existent in N to being the most abundant subpopulation of T. Gene set enrichment analysis (GSEA) of cluster 2 showed the highest enrichment scores in MARCO+ macrophages to be lysosome, proteasome, oxidative phosphorylation (OXPHOS) and citrate cycle (TCA cycle) (Figure 2H), consistent with the functions of MARCO in phagocytosis and clearance (37). Here, MARCO is linked to breast cancer.