Analysis of coordination of cell movements in unwounded monolayers and between sparse cells. (A and B) Mean normalized cell pair separation distance (A) and mean velocity correlation (B) for confluent, unwounded MCF10A monolayers on soft (3 kPa) and stiff (65 kPa) substrates compared with those for cells within 160 µm of wound edge undergoing collective migration at 12 h after wounding. (C) Mean velocity correlation for sparsely seeded MCF10A cells on various substrate stiffness. N = number of experiments. All nonoverlapping error bars (95% SEM) are statistically significant with P < 0.05.