Because we had previously shown that perforin and granzyme B transcripts from lung CD8+ T cells were increased in severe COPD[7], we were surprised to see that TLR-stimulation did not increase production of perforin or granzyme B. It is possible that perforin and granzyme were increased in the intracellular granules of the CD8+ T cells but release of these molecules into the supernatant requires CD8+ degranulation. This evidence concerns the gene PRF1 and chronic obstructive pulmonary disease.