This balance may be disturbed in JIA, as the activity of ECM-degrading factors in these patients is high, including matrix metalloproteinases (MMP), a disintegrin-like and metalloproteinase with thrombospondin motifs (ADAMTS), or reactive oxygen species (ROSs), which are not equalized by the activity of factors stimulating ECM synthesis, including insulin-like growth factor-1 (IGF-1), transforming growth factor-β (TGF-β), or platelet-derived growth factor-BB (PDGF-BB) [3,6,7,8,9,10]. Here, IGF1 is linked to juvenile idiopathic arthritis.