MUC5B and idiopathic interstitial pneumonia: Other genetic associations with IPF have been confirmed by genome-wide association studies (GWAS), including mutations in the promoter region of mucin 5B (MUC5B), a gel-forming protein fund in the secretions of the respiratory tract, and in toll interacting protein (TOLLIP), which participates in the regulation of the immune system and is associated with IPF susceptibility [24].