Neurofibromatosis type 2 (NF2) is an autosomal dominant disease characterized by the development of central nervous system tumours. The NF2 gene was recently cloned and found to encode a protein, schwannomin (or merlin), with homology to the band 4.1 superfamily. This superfamily of proteins includes ezrin, moesin, radixin, and talin, as well as several protein tyrosine phosphatases. How does a cytoskeleton-associated protein act as a tumour suppressor? While this fundamental question remains unanswered, recent studies have begun to address key questions regarding the function of schwannomin. In this review, we examine what is known about the band 4.1 superfamily and how this information pertains to schwannomin. In addition, we summarize recent studies of schwannomin itself.