Fig. 2. Schematic description of a mechanical model of neutrophil phagocytosis. The cell-bead interface is stabilized by adhesion sites that act as anchors to the internal cytoskeleton. Myosin motors draw down F-actin, thus pulling the bead into the cell or, equivalently, the cell onto the bead. Polymerization of new actin near the contact line (the leading edge) drives protrusion around the bead.