TNFSF13B and interstitial lung disease: In addition, Zhang et al. found that IFNα was correlated to BAFF in patients with MDA5+ DM and that increased levels of BAFF were associated with higher concentrations of Krebs von den Lungen-6 (KL-6) (71), a potential biomarker that reflects the severity of connective tissue disease-associated ILD (72).