CD4 and chronic obstructive pulmonary disease: Hierarchical clustering analysis of unstimulated RNA transcripts from isolated lung CD4+ T cells revealed that a subset of subjects, mostly with COPD, were virtually devoid of transcripts for TH1, TH2, TH17, and T regulatory (TReg) transcription factors and cytokines, although they expressed some upregulated transcripts that argued against global shutdown of RNA synthesis.