In conclusion, this study shows that LRG, a novel serum biomarker, better reflects endoscopic activity during adalimumab treatment than CRP or fCal among IBD patients, indicating that LRG can be considered a potential biomarker to monitor disease activity during induction and maintenance therapy and can be incorporated in the treat-to-target strategy for the clinical management of IBD. The gene discussed is CRP; the disease is inflammatory bowel disease.