In contrast to the narrow spectra of benign schwannoma and meningioma tumours in neurofibromatosis patients, Nf2 heterozygous mice develop a variety of malignant tumours with high rates of metastasis9, which are dependent on the Merlin-mediated stabilization of adherens junctions10, the control of cadherin-mediated cell:cell contact11, and the activation of Rac12. The gene discussed is NF2; the disease is schwannoma.