A direct role for EphB4 in tumour angiogenesis has been suggested by experiments showing that A375 melanomas form smaller tumours in the presence of soluble EphB4 [32] possibly because the soluble EphB4 interferes with binding of endogenous EphB4 on tumour cells to ephrin-B2 on endothelial cells. Here, EFNB2 is linked to melanoma.