These were the chemokine CCL2 (Fig. 6I), in agreement with the results of stimulated protein secretion in COPD subjects as a whole (Fig. 2), and CCAAT-enhancer-binding protein homologous protein (CHOP) (Fig. 6J). Thus, the virtually absent expression of mRNA transcripts for IFN-γ and multiple transcription factors seen in the Group A subjects does not reflect a global inability to elaborate any RNA transcripts. Here, DDIT3 is linked to chronic obstructive pulmonary disease.