For female COPD the top genes (see Table S3) with a 2.5-fold higher expression were CYP1B1, a cytochrome P450 member, which is involved in steroid metabolism, FGFBP1, a binding protein for fibroblast growth factor, which may enhance the activity of FGF, CEACAM5, a cell adhesion molecule, and CA12, a carbonic anhydrase involved in conversion of CO2. Here, CEACAM5 is linked to chronic obstructive pulmonary disease.