Figure 4.

Exploratory assessment of inflammatory modulatory proteins, chemokines, and growth factors in plasma samples. Inflammatory markers were assessed from the plasma in nonsmoking healthy controls (black), e-cigarette users at baseline (red) and after 2 wk of reduced e-cigarette usage (blue). Only the analytes with statistically significant differences by Student’s t test (without controlling for multiple comparisons) were included in this figure and are further separated into cytokines (A–E), chemokines (F–I), and growth factors (J–L). Paired lines between e-cigarette and reduced dose represent the change in the levels in the same individual after reducing the e-cigarette dose. Error bars represent the means ± SD. *P < 0.05, **P < 0.01, and ****P < 0.0001, as determined by Student’s t test.