S100A9 and acute lymphoblastic leukemia: S100A9 expression in the sJIA group was significantly higher than that in the control group (60,741±53,847 vs 5,081±2,809 pg/mL, P=0.000) and ALL group (5,204±4,205 pg/mL, P=0.0000) but showed no significant difference compared to the SIF group (35,942±12,517 pg/mL, P=0.052), KD group (31,904±16,135 pg/mL, P=0.051), and JIA group (38,681±24,496 pg/mL, P=0.059) (Figure 1).