Metastatic invasion is driven by the reorganization of the cytoskeleton and the formation of cell-membrane protrusions called ‘invadopodia’. Invadopodia assembly is regulated by protein tyrosine kinases, but little is known about the roles of tyrosine phosphatases. An improved understanding of the mechanisms that form invadopodia could be used to combat tumor spread. To reduce this gap, researchers recently examined the role that the tyrosine phosphatase Shp1 plays in this process. They found that Shp1 localized to invadopodia and that this localization was facilitated by a phosphoinositide metabolite, glycerophosphoinositol (GroPIns). Once there, Shp1 associated with and dephosphorylated cortactin, which reduced the formation and extracellular matrix degradation activity of invadopodia. Treatment with GroPIns inhibited tumor invasion in mice when Shp1 was present, but this effect was dependent on the presence of Shp1. These results suggest that Shp1 can be considered a regulator of melanoma cell invasiveness and thus a potential target for antimetastatic drugs as well as suggest GroPIns as a lead for drug development.