For example, Yujie41 found that elevated RDW is correlated with inflammatory markers such as CRP and ESR in patients with rheumatoid arthritis, and Zhide13 show that RDW is up‐regulated and positively associated with ESR, CRP, IgM, and SLEDAI in SLE patients. The gene discussed is CD40LG; the disease is systemic lupus erythematosus.