The levels of IL-10 among the cases were significantly higher than in the controls during the progression of HFMD from days 2 to 5 as follows: 16.86 (12.48∼27.45) vs. 10.18 (7.42∼16.70), 44.66 (41.33∼47.97) vs. 22.50 (19.77∼29.25), 77.00 (68.93∼82.14) vs. 34.64 (32.97∼39.00), and 57.20 (47.97∼62.42) vs. 35.65 (29.77∼42.99), respectively (P = 0.001 for the 2nd day and P<0.001 for the other days). The gene discussed is IL10; the disease is hand, foot and mouth disease.