Since there are no data available on the expression of this important cytokine signal inhibitor in COPD, the aim of the present study was to address the transcriptional expression level of SOCS-3 along with SOCS-4 and SOCS-5 in bronchial tissues of a previously characterized cohort of COPD patients [12,22]. This evidence concerns the gene SOCS3 and chronic obstructive pulmonary disease.