FMNL formins boost lamellipodial force generation

Actin polymerization in lamellipodia of cells is regulated by the Arp2/3 complex and FMNL family formins. Here the authors show that both FMNL2 and FMNL3 contribute to lamellipodium protrusion and structure, and abolishing FMNL2/3 reduces protrusion force generation and migration, without affecting Arp2/3 incorporation.