The effects of anastellin and endostatin on endothelial cell migration are additive. Endothelial cells were seeded on collagen-coated transwells in the presence of endostatin or anastellin either individually or in combination. Peptides were added to both chambers at the time of seeding. After 1 hour, 10 ng/ml VEGF was added to the lower chamber. Control wells (C) received no peptides and no VEGF and represent baseline migration. Positive control wells (+) were set at 1 and represent VEGF dependent migration. After 4 hours, plates were fixed, stained and the number of cells migrating to the underside of the filter were counted in three 10× fields in each of triplicate wells. Bars represent standard error of the mean from data obtained from 7 separate experiments, n = 63.