Influence of brake wear particles on the tight junction protein occludin. A) Non exposed cells. B) Cells exposed to a „full stop“ with 8 repetitions. The graph on the bottom shows the quantifications of occludin (B). Each value represents the median of the 25%- and the 75%-quantile from 2 ("full stop 4x" and "no stop run") or 4 (all the other conditions) experiments.