Two Poles and a Compass

Rho GTPases control fundamental aspects of neutrophil chemotaxis: establishment of front and back and orientation toward the chemoattractant. Two reports in this issue show that activated Cdc42 at the leading edge helps orient the cell's axis in a signaling complex with G beta gamma, PAK1, and PIX alpha; while Rho, activated via G alpha 13, mediates formation of the uropod, which then interacts by mutual negative feedback with the front to reinforce polarization (Li et al., 2003 [this issue of Cell]; Xu et al., [this issue of Cell]).