CD163 and nasopharyngeal carcinoma: Out of 90 NPC cases, 87 specimens (96.6%) expressed CD163+ cells, 57 specimens (63.3%) stained ISG15 mainly in tumor cells and infiltrating immune cells, and 49 specimens (54.4%) expressed ISG15+ CD163+ cells, which suspected to be macrophages based on their morphology as well (Figure 5C).