Following the recommendations of Hensor et al. (2018) (who found that, out of the individual components of the DAS28, it is CRP and SJC28 that are the most predictive of imaging‐detected synovitis) and of Massey et al. (2018) (who found that only ESR and SJC28 are highly heritable), we based our transformation of CRP, SJC28, and ESR on their contribution to the DAS28. The gene discussed is CRP; the disease is synovitis.