CD68 and neoplasm: The mIHC assay includes several macrophage markers located in the cell membrane, cytoplasm or nucleus (Fig. 7a): cytokeratin markers (Pan-CK) for tumor cells60; CD68, a highly expressed pan-macrophage marker which primarily localizes on lysosomes and endosomes, and also localizes on cell membranes61; interferon regulatory factor 8 (IRF8), also known as interferon consensus sequence-binding protein (ICSBP), an M1-like macrophage marker62; CD163 and CD206 that are upregulated in M2-like macrophages.