HMGB1 and cancer: Although HMGB1 staining existed only in the nucleus in normal mucosa, co-expression of nuclear and cytoplasmic HMGB1 (co-expression pattern) existed in a subset of cancer tissues (12/65 [18.5%]), whereas most of the cancer tissues only showed nuclear staining of HMGB1 (nuclear expression pattern; 53/65 [81.5%]; Table 2, Fig. 4).