Reynisdottir et al., employing a different approach, analyzed the findings of high-resolution computed tomography (HRCT) in 70 patients with early, untreated RA who were positive for anticitrullinated proteins (ACPA-positive) compared with 35 patients with early, untreated ACPA-negative RA [13]. The gene discussed is PRTN3; the disease is rheumatoid arthritis.