Dynamic Rac1 inhibition by CYRI helps cells drink, but stops them from driving

In this issue, Le et al. (2021. J. Cell Biol.https://doi.org/10.1083/jcb.202012114) describe a new role for the recently discovered protein CYRI in controlling the protrusions that allow cells to engulf extracellular fluid by macropinocytosis. This study helps explain how these structures are disassembled, but also uncovers a new mechanism linking the ability of cells to drink and their capacity for invasive migration.