Further study is required to investigate the role of SP-D in the pathogenic process of PM/DM-associated ILD in patients with anti-MDA5 antibody, and to validate whether the measurement of serum SP-D levels is beneficial for prediction of outcomes in each MSA among patients with PM/DM-associated ILD in daily practice if the test is approved for clinical use in many countries over the world. Here, SFTPD is linked to interstitial lung disease.