FN1 and cystic fibrosis: All CF developmental ages possessed similar migration rates on control gelatin–fibronectin substrates (Figure 2D) (fetal CFs: 1.96% ± 0.22%/hr; neonatal CFs: 2.89% ± 0.35%/hr; and adult CFs: 2.21% ± 0.28%/hr).