Given that CDC42-GTP promotes F-actin polymerization and filopodia formation (Jacquemet et al, 2016), facilitating cancer cell migration and survival at distant metastatic sites (Shibue et al, 2012), we found that Reelin treatment upregulated GTP-CDC42 in control cells, with no change observed in LRP8 knockdown cells. Here, CDC42 is linked to cancer.