DEGs shared across COPD, LUSC, and LUAD (15 genes) were classified into 9 categories: “cell adhesion molecule,” “extracellular matrix protein,” “gene-specific transcriptional regulator,” “intercellular signal molecule,” “metabolite interconversion enzyme,” “protein modifying enzyme,” “protein-binding activity modulator,” “scaffold/adaptor protein” and “transporter” (Fig. 2B). The gene discussed is PROS1; the disease is chronic obstructive pulmonary disease.