While the direct effect of S100B on schwannoma growth has not been studied mechanistically, it has been established that the protumorigenic effect of S100B in melanoma and glioma involves inhibition of p53 tumor suppressor protein activity, stimulation of mitogenic kinases activity (Ndr and Akt), and macrophage chemoattraction (38, 39). The gene discussed is S100B; the disease is schwannoma.