The transformation of normal melanocytes, or melanocyte stem cells, to melanoma, is a
complex process involving multiple mechanisms. Loss of tumor suppressor proteins, which
function as brakes on cell growth, migration, or cell survival, was recognized early on as an
important mechanism for initiation and progression of melanoma. Semaphorins and their
cognate receptors, Plexins and neuropilins, are involved in neuronal pathfinding, immune
function, and tumor progression through effects on blood vessel growth and cell migration …