Interestingly, the results of our studies do not show a plateau trend either at high concentrations (50, 100 ng/ml) or long incubation times (45, 90 min) of IL-8, suggesting the effect of metastatic cancer cells on endothelial cell barrier could potentially be greater if the cancer cells are in close proximity to the endothelium for longer or if local concentrations of cytokines secreted by melanoma cells reach higher levels than the ones tested here. Here, CXCL8 is linked to melanoma.