IL13 and chronic obstructive pulmonary disease: The genesets were then validated against three transcriptomics datasets representing (1) an in vitro 3D human lung tissue (MucilAirTM) acute exposure to tobacco smoke or electronic cigarette aerosol, (2) a repeated incubation in vitro with IL-13 a known inducer of the mucus hypersecretion phenotype18, and (3) a COPD lung biopsies dataset19.