Fig. 3.

Expression value of identified genes in publicly samples. The box plot presents the normalized expression values of the 15 identified genes in publicly available samples for non-smokers (green), smokers (yellow), and chronic obstructive pulmonary disease (COPD) subjects (red). The box plot presents the median (line) and 25th and 75th percentiles (box); the whiskers are the 5th and 95th percentiles; and the outliers are denoted by open circles. One-way ANOVA with subsequent Tukey’s honest significant difference post-hoc analysis revealed differences between NS and SMK or COPD (*p < 0.05) and between SMK and COPD (†p < 0.05). NS, non-smokers; SMK, current smokers; COPD, COPD subjects