Figure 2 shows the progression of chest HRCT findings in the anti-MDA5 antibody-positive and antibody-negative cases that progressed to PPF. Additionally, a comparative analysis was conducted between the anti-MDA5 antibody-positive ILD group (all cases being A/S-ILD) and the anti-MDA5 antibody-negative A/S-ILD cases, yielding similar results (Table S2). The gene discussed is IFIH1; the disease is interstitial lung disease.