We discovered a new way that filopodia work. Filopodia are thin, finger-like protrusions that cells use as “feelers” to sense and grab their surroundings. They are found on many cell types and are especially common on moving immune cells and cancer cells where they facilitate invasion.

We found that filopodia can rotate because their inner support structure—made of actin fibers—can twist like a rope. This was the first clear evidence that a bundled set of actin fibers can twist in this way. We also suggested a simple physical explanation for how the twisting happens.

This twisting matters because it can help the cell pull on things it touches—similar to how a twisted rubber band tends to tighten and pull as it relaxes.

• Nature Communications, 2022, Leijnse et al.
• PNAS 2015, Leijnse et al.
• Review in TCB : Ruhoff et al. 2025
• Review in Cytoskeleton 2015 Leijnse et al.