Fig. 5.

TNF-α, MMP-9, MMP-3, and MMP-1 levels in culture media over 28 days during which repeated exposures of whole aerosol/smoke (1:17 dilution) /humidified air were applied. Analysis of pro-inflammatory markers from T23-28 were excluded for 90 puffs of 3R4F smoke, due to significantly high levels of cytotoxicity. Levels are expressed as fold change compared to air control response. Note the y-axis scale differences between 3R4F and myblu graphs. Key to significance. +, indicates a significant difference where the adjusted p < 0.05. Error bars are the standard error of the mean.