SOAT1 and chronic obstructive pulmonary disease: Several studies demonstrate that chronic exposure to cigarette smoke activates airway epithelium triggering different signaling pathways involved in the inflammatory and fibrotic responses associated to COPD development, such as signal transducer and activator of transcription (STAT) [3, 32], Janus tyrosine kinase (JAK) [3, 32], and the nuclear factor-κB (NF-κB) [33].