CSE induces transmigration of neutrophils through HUVECs. 5 × 105 calcein-AM labeled PMNs were placed in the top well on HUVEC layers and the indicated reagent (CSE or fMLP) was added to the bottom well of the transmigration system. After one hour incubation at 37°C in 5% CO2, fluorescence in 100 μl from each bottom well was measured. Data was standardized to the fluorescence of 100 μl PMNs (5 × 105 cells). (A) CSE (OD 0.06-0.24) induces transmigration of PMNs (**, p < 0.01 CSE vs. control). FMLP was tested as a positive control (+, p < 0.01 fMLP vs. control). Legend: each color represents a different donor (N = 4-8, n = 2). (B) Standardizing the data of figure 4A to an index where the transmigration under control situation is 100%, CSE incubation leads to approximately a 1.5-fold higher migratory capacity (***, p < 0.001 CSE vs. control).