MRC1 and neoplasm: Wagner et al. analyzed 144 human breast tumor and 50 non-tumor tissue samples by using single-cell proteomics, identifying the following five myeloid clusters: (1) CD14-expressing classic (M06, CD14+CD16−) and inflammatory monocytes (M15, CD14intCD16+), (2) early immigrant macrophages (M03, M11, M13, HLA-DRintCD192+), (3) tissue-resident macrophages (M08, M09, M16, CD206+HLA-DRint), (4) TAMs (M01, M02, M04, M14, M17, CD64highHLA-DRhigh), and (5) MDSCs (M07, M10, M12, HLA-DR−/low) [26].