To further reveal genes responsible for COPD in particular, we showed that the top COPD-associated DEGs among immune cells were from monocytes, including nuclear factor-kappa B (NF-κB) signaling genes such as REL, IL1B, KLF4 and FLNA; among non-immune cells, the top DEGs were from AT2s and club cells, including AZGP1, SNRPG, HNRNPM, EIF3E, TIE1, and IL7R (Fig. 2C). The gene discussed is NFKB1; the disease is chronic obstructive pulmonary disease.