BTK and chronic obstructive pulmonary disease: KEGG pathway enrichment (FDR = 0.05) highlighted a central role of NF-κB pathway mediated inflammation in COPD (P=4.78×10−4) and ACO (P=3.44×10−3) (both p-values from hypergeometric test, BH corrected), with ACO showing upregulation of NF-κB signalling genes LY96, TRAF1, TRAF5, BTK, NFKBIA, and CHUK (Supplementary Table S3, Supplementary Figure S5a).