RAC1 and neoplasm: Coro1C was an interesting hit, as the hematopoietic homolog, Coro1A (but not Coro1B), has been found to form a complex with RhoGDI and Rac1 in the cytosol, causing release of Rac1 from the GDI and its translocation to the plasma membrane (Castro-Castro et al., 2011), and Coro1C affects Rac1 in tumor cells by an unknown mechanism (Wang et al., 2013).