MUC5B and idiopathic interstitial pneumonia: In this context, the most validated and strongest genetic risk factor for both familial and sporadic IPF, is represented by the single nucleotide polymorphism rs35705950 in the promoter region of the mucin 5B (MUC5B) gene (Steele et al., 2011; Allen et al., 2017; Allen et al., 2020).