SFTPD and idiopathic pulmonary fibrosis: Ikeda et al., among 163 IPF patients receiving pirfenidone, showed that lower baseline BMI and FVC were poor prognostic factors ([FVC] OR, 0.93; 95% CI 0.916–0.971; p < 0.0001; [BMI] OR, 0.849; 95% CI 0.723–0.998; p = 0.0469) for DP (≥ 10% relative decline in FVC from baseline and/or death over 1 year after antifibrotic therapy) in the multivariate logistic analysis adjusted for smoking, alveolar-arterial oxygen gradient, and surfactant protein D [12].