Moreover, since small airways have been implicated in the pathogenesis of diseases that lack large animal models such as asthma, chronic obstructive pulmonary disease (COPD), and MUC5B promoter variant rs35705950-related idiopathic pulmonary fibrosis (IPF), it would be important to translate this methodology to study humans with these diseases (65, 66). This evidence concerns the gene MUC5B and chronic obstructive pulmonary disease.