Table 1.

Summary of experimental data.

System	No. of islands	Data name
Low density	4	low_density_islands
High density	4	high_density_islands
Cytochalasin D	6	cytoD_islands
CN03	8	cn03_islands

All experiments use islands of MDCK cells patterned on substrates having Young’s modulus of 6 kPa. Images, velocities, cell-substrate tractions, and monolayer stresses are provided for all experiments. Spatial resolution: 12 and 8 pixels (7.9 and 5.2 μm) for velocities and tractions/stresses respectively. Temporal resolution: 10 minutes.