Figure 1From: Cigarette smoke exposure inhibits extracellular MMP-2 (gelatinase A) activity in human lung fibroblastsPanel of representative phase contrast micrographs of HFL-1 cells after 24 hours of CSE incubation. A) Untreated Control; B) 1% CSE; C) 2% CSE; D) 5% CSE; E: 10% CSE; F: 20% CSE. Magnifications 20×.Back to article page