CD163 and brain cancer: Inflammatory macrometastases in the brain expressed high levels of transcripts for activated M2 macrophages (including significant upregulation of the macrophage marker CD163 in brain vs. lung metastases, log-fold change 5.5, FDR-adjusted p-value < 0.004) which have been described as having anti-inflammatory or tumour supporting activities, including in malignant brain tumours (although it is important to recognise that it may be difficult to distinguish between microglia and macrophages, both of monocyte lineage, using these methods)38.