Accumulation of foamy cells in smokers – a strong comorbidity factor in lung infections (Wilson et al., 2011) – reflects impaired lipid cellular metabolism, as reduced levels of apolipoprotein A1 (ApoA1) are found in the bronchoalveolar lavage fluid of patients with idiopathic pulmonary fibrosis (IPF) (Kim et al., 2010). This evidence concerns the gene APOA1 and idiopathic pulmonary fibrosis.