HMGB1 and chronic obstructive pulmonary disease: Furthermore, immunohistochemistry showed that HMGB1 was detected almost only in the nuclei of macrophages in Non‐smoker group, while it was detected both in the cytoplasm and the nuclei of macrophages in COPD and Smoker groups (Figure 1A), indicating that HMGB1 was translocated from the nuclei to the cytoplasm in the latter two groups.