Fig. 1

Volcano plot displaying differentially abundant proteins in subjects with non-productive cough. The most prominent proteins for separating those with non-productive cough and those without cough are shown in the top left and top right of the plot and are coloured blue. Proteins that differ between the groups to a smaller extent but have a significant p-value are coloured green. The negative log₁₀ of the p-value is plotted on the y-axis and the difference (log₂ fold change) on the x-axis, based on the t-test between the two groups adjusted for sex and the investigator