Focus Issue: Cells on the Move

Science 's STKE explores the molecular mechanisms that allow cells to navigate and migrate in a particular direction. New models for forming cellular extensions called filopodia that initiate migration, along with methods for analysis of the proteomic differences between the cell body and cellular protrusions (pseudopodia), are highlighted. The processes by which groups of cells, as well as individual cells, navigate in a particular direction are also featured.