The Cas family of multiadaptor and scaffold molecules has an essential role in intracellular signaling events. Although these proteins do not have enzymatic or transcriptional activity, they spatially and temporally control signaling events through their ability to undergo changes in phosphorylation and to associate with effectors proteins in multimolecular complexes. The involvement of p130Cas in cell motility as a component of the integrin signaling machinery is well established. Here, we discuss recent developments that highlight a fundamental role in cell transformation and microbial pathogenesis and the implications of these developments on p130Cas function under normal and pathological conditions.