Perforin, granzyme B, and FasL mRNA expression by isolated peripheral CD8+/CD16- cells. For each subject, total RNA was extracted from magnetically isolated CD8+/CD16- cells. mRNA expression of granzyme B, perforin, and FasL was assessed by real-time PCR, using 18S rRNA as housekeeping gene and compared using 2-ΔΔCt method. Columns represent mean ± SEM. *p = 0.02; **p = 0.05. Normal non-smokers (white), normal smokers (black), and emphysematous smokers (grey).