showed that LRG1 promoted apoptosis and autophagy in cardiomyocytes under hypoxic conditions by regulating hypoxia‐inducible factor‐1α (HIF‐1α).[22] Additionally, LRG1 serves as an inflammatory biomarker in autoimmune diseases, including pediatric inflammatory bowel disease,[23] systemic juvenile idiopathic arthritis[24] and rheumatoid arthritis, and can monitor disease activity even in subsets with normal C‐reactive protein (CRP) levels.[25]. Here, LRG1 is linked to systemic-onset juvenile idiopathic arthritis.