We verified the mRNA levels of the top 10 hub genes in the COPD group, and we found that expression of 8 hub genes (RPLP0, RPL5, RPL32, RPL13A, FAU, RPL32, RPS21 and RPS11) was significantly downregulated in COPD tissues compared to the normal tissue consisted with the prediction results (Figures 6A–J). This evidence concerns the gene RPS21 and chronic obstructive pulmonary disease.