Arf6-dependent membrane traffic and wound-induced integrin engagement control Cdc42 activation at the wound edge. Cdc42 accumulation and activation at the wound edge result from wound-induced integrin signaling (Etienne-Manneville and Hall, 2001) and Arf6-dependent vesicular delivery of Cdc42 and its GEF βPIX. We propose that βPIX interaction with Scrib (Osmani et al., 2006) and phosphorylation by Src (Feng et al., 2006) at the wound edge promotes βPIX GEF activity toward Cdc42 and thus leads to the generation of a Cdc42-mediated polarity signal that involves Par6, aPKC, and APC (Etienne-Manneville and Hall, 2003).