Melanoma cells express low-affinity neurotrophin receptors p75NTR and TrKc, which are positively regulated by nerve growth factor (NGF) and neutrophin-3 (NT-3), leading to enhanced production of extracellular matrix (ECM) degradative enzymes such as heparanase and culminating in the breakdown of the blood-brain barrier (BBB). Here, NGF is linked to melanoma.