The molecular link between the signalling pathway regulating the formation
of filopodia and the initiation of local actin polymerization has been eluc
idated: N-WASP, a close homologue of WASP, which is the product of the gene
responsible for the Wiskott-Aldrich syndrome, mediates a direct connection
between the small G-protein Cdc42 and the Arp2/3 complex.