WFDC2 and kidney disorder: HE4 levels were significantly higher in moderate to severe disease activities (57.4 pmol/L, IQR 37.7–164.5) than in mild disease activities (38.8 pmol/L, IQR 30.1–48.5) or HCs (38.9 pmol/L, IQR 34.0–46.1), as well as in active renal disease activities (77.2 pmol/L, IQR 47.4–224.1) than in inactive renal disease activities (36.1 pmol/L, IQR 27.8–46.7).