In contrast, in patients with anti-MDA5 antibodies, isolated anti-Ro52 positivity almost completely corresponded to anti-Ro52 positivity, which was associated with an increased frequency of RP-ILD and respiratory insufficiency at initial presentation, namely, a lower PaO2/FiO2 ratio and higher A-aDO2. The gene discussed is TRIM21; the disease is interstitial lung disease.