Movie 1.

MDA-MB-231 cells use a cortex-driven mechanism to support nuclear transit through constrictions. Representative time-lapse sequence of an MDA-MB-231 cell expressing mCherry2-Actinchromobody (magenta) and mNeonGreen-H2B Histone (cyan) transiting through a ≤2×5 μm² constriction b contracting the rear cortex to push the nucleus forward. Scale bar: 10 μm.