Protein concentration and mRNA expression of IL-8 in the cervical tissue. Box and whisker plots represent (A) the protein concentration of IL-8 (picograms/mg of total protein) and (B) expression of the IL-8 mRNA (expressed as the product/28S intensity ratio) in the cervical tissue of the study groups. The groups are: preterm labour (PTL), term labour (TL), preterm not in labour (PTnotL), term not in labour (TnotL). The number of patients analysed in each group is marked in each bar in the bar chart. The box represents median value with 25%–75% of all data falling within the box. The whiskers extend to the non-outlier range. Outliers are marked as circles. Significant differences between the groups are shown above the box plots.