Heatmap in Fig. 4D details the top 30 most pronounced DEGs in HDM-CS, with upregulated genes including COPD marker Mmp12, type 2 marker Il13, eosinophil gene Car6, acute reactant Saa4, and Npy. Downregulated genes include those in ECM formation (Fbn2), protease inhibition (Cst8), and vascular regulation (Apold1). The gene discussed is SAA4; the disease is chronic obstructive pulmonary disease.