The HMGB1 levels in the EV71-infected severe group (7.48 ± 1.80 ng/mL) and the critical HFMD group (11.50 ± 2.38 ng/mL) were significantly higher than those in the mild (5.91 ± 1.27 ng/mL) and control (5.28 ± 1.54 ng/mL) groups (P < .01). Here, HMGB1 is linked to hand, foot and mouth disease.